Chronic plaque psoriasis in adults: Treatment of disease amenable to topical therapy

INTRODUCTION — 

Psoriasis is a multisystem chronic inflammatory disorder with a variety of clinical presentations. Chronic plaque psoriasis, the most common presentation of psoriasis, classically presents with well-defined plaques on the skin (picture 1A-H). The major treatment modalities for chronic plaque psoriasis include topical therapy, systemic therapy, and phototherapy.

The extent of skin involvement plays an important role in treatment selection. For most patients with a limited degree of skin involvement, topical therapy is our preferred initial mode of therapy. However, the location(s) of skin involvement, comorbidities such as psoriatic arthritis, and other factors can support different approaches to therapy. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Selecting the primary mode of therapy' and 'Identifying disease appropriate for topical therapy' below.)

The approach to treatment selection for chronic plaque psoriasis that is amenable to topical therapy will be reviewed here. Selection of the preferred mode of psoriasis therapy, general principles of therapy, and the therapeutic approach to disease requiring systemic therapy or phototherapy are reviewed separately.

●(See "Chronic plaque psoriasis in adults: Overview of management".)

●(See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy".)

The management of other presentations of psoriasis is reviewed separately.

●(See "Guttate psoriasis", section on 'Treatment'.)

●(See "Nail psoriasis", section on 'Treatment'.)

●(See "Erythrodermic psoriasis in adults", section on 'Management'.)

●(See "Pustular psoriasis: Management".)

●(See "Treatment of psoriatic arthritis".)

●(See "Treatment of peripheral psoriatic arthritis".)

The management of chronic plaque psoriasis in special populations is also reviewed separately.

●Children (see "Psoriasis in children: Management of chronic plaque psoriasis")

●Pregnant individuals (see "Management of psoriasis in pregnancy")

●Individuals with hepatitis, human immunodeficiency virus (HIV) infection, latent tuberculosis, or malignancy (see "Treatment selection for moderate to severe plaque psoriasis in special populations")

IDENTIFYING DISEASE APPROPRIATE FOR TOPICAL THERAPY — 

Treatments for chronic plaque psoriasis include topical therapies, systemic therapies, and phototherapy (table 1A-B). Selection of the primary mode of therapy is an individualized decision that considers the extent and location of skin involvement, disease complications, patient abilities and preferences, patient comorbidities (eg, psoriatic arthritis), and treatment availability (algorithm 1). (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Selecting the primary mode of therapy'.)

The major advantage of topical therapy is the favorable drug adverse effect profile of many topical agents. In addition, in contrast to phototherapy, topical therapy does not require special equipment or frequent office visits.

Examples of factors that guide our selection of topical therapy for initial therapy include:

●In general, topical therapy is most feasible for patients with chronic plaque psoriasis that involves a limited area of skin (eg, <3 to 5 percent of the body surface area [BSA]). Application of topical therapy to large body areas can be difficult and may not be practical or feasible. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Extent and location of skin involvement'.)

●Achieving satisfactory clinical improvement with topical therapy alone can be more challenging when chronic plaque psoriasis involves certain body areas (eg, palms, soles, scalp) or multiple body areas. Factors such as physical limitations, risk for adverse effects (eg, corticosteroid-induced skin atrophy), and patient preference also influence the feasibility of topical therapy. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Extent and location of skin involvement' and "Chronic plaque psoriasis in adults: Overview of management", section on 'Patient ability and preference'.)

Psoriatic arthritis may result in the use of a systemic drug even when skin involvement is limited. Some patients may still require adjunctive topical treatment for resistant or residual skin disease. (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy", section on 'Patients with psoriatic arthritis'.)

SUPPORTING EFFICACY OF TOPICAL THERAPY — 

The efficacy of topical therapy depends on adherence to the treatment regimen. Thus, it is critical to identify a regimen that is acceptable to the patient.

Drug vehicle selection — The topical drug vehicle (eg, cream, lotion, gel, solution, oil, foam, shampoo, spray solution) selected should support ease of application to the affected area, minimize risk for treatment intolerance, and address cosmetic concerns of the patient. Advantages and disadvantages of specific drug vehicles are reviewed separately. (See "Topical corticosteroids: Use and adverse effects", section on 'Vehicles and formulations'.)

Patient involvement and clinician understanding of patient preferences and habits are essential for appropriate vehicle selection. As an example, foams or solutions are often considered easier to apply to hair-bearing areas (eg, scalp) than ointments. However, some patients who use oils or ointments for general scalp and hair care or who find foams or solutions too drying for their hair type may prefer an oil or ointment vehicle for scalp involvement. In addition, a topical corticosteroid shampoo is a less favorable primary treatment for patients who do not wash their hair more than once per week.

Patient education — Careful review of the application regimen, expected outcomes, potential adverse effects, and patient concerns may support successful use of topical therapy. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Patient education and counseling'.)

Simplification of regimen — Patients with disease manifestations typically managed with different topical drugs or drug vehicles (eg, scalp plaques and intertriginous plaques) may benefit from reducing the number of topical therapies. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Disease in multiple locations'.)

As an example, provided close clinical follow-up for adverse effects is feasible, we sometimes use an abbreviated course of a higher-potency topical corticosteroid in body sites normally treated with lower-potency topical corticosteroids (eg, intertriginous regions) for patients requiring a high-potency topical corticosteroid for psoriasis in other body areas. (See 'Topical corticosteroids' below.)

Follow-up — Providing opportunities to assess the response to therapy, adjust therapy, and address patient concerns or questions may support effective use of topical therapy. In our experience, early contact (in person, phone, or electronic) with the patient one week after prescribing a new topical agent helps to support effective use of topical therapy.

Subsequent follow-up frequency is dependent on the treatment regimen, response, and risk for adverse effects. We typically aim to reassess patients within the first few months of treatment to evaluate the response, ensure appropriate medication use, address questions, and make any necessary treatment adjustments. Clinically significant improvement is often expected within the first several weeks of topical treatment.

For some patients, once a stable, tolerable, and effective topical regimen is achieved, once-yearly follow-up may be sufficient. However, factors such as a need to monitor for adverse effects (eg, topical corticosteroid-induced skin atrophy in at-risk sites) and resistant or unstable disease support more frequent reassessment. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Follow-up'.)

TOPICAL THERAPY

Initial treatment selection — The clinical presentation influences the initial selection of a topical regimen. Topical corticosteroids, topical vitamin D analogs, topical taparinof, topical roflumilast, topical calcineurin inhibitors, and topical tazarotene are the mainstays of topical therapy (table 1A). (See 'Treatment options' below.)

Other topical agents are generally reserved for adjunctive therapy. (See 'Adjunctive interventions' below.)

Most plaques — We typically prescribe a high-potency topical corticosteroid for the initial treatment of plaques in sites at low risk for corticosteroid-induced skin atrophy (eg, nonfacial, nonintertriginous plaques) because of the rapid onset of efficacy, wide availability, and generally reasonable cost of some topical corticosteroids.

Alternatively, topical corticosteroid therapy can be combined with a topical vitamin D analog. Combination therapy can be more effective than topical corticosteroid therapy alone but can increase the cost or complexity of the treatment regimen, making it more difficult for patients to obtain or adhere to treatment. Use of fixed combination products can simplify combination therapy (table 1A). (See 'Topical corticosteroids' below and 'Topical corticosteroid plus topical vitamin D analog' below.)

However, other topical therapies used as monotherapy, such as vitamin D analog, roflumilast, and tapinarof, can also be effective. Thus, selection of one of these drugs for initial therapy is a reasonable alternative, particularly when tolerance of risk for corticosteroid adverse effects is a concern. The higher cost of these therapies compared with some topical corticosteroids may be a limiting factor. Additionally, topical vitamin D analog monotherapy appears less effective and less well tolerated than combined topical corticosteroid and topical vitamin D analog therapy. The relative efficacy of roflumilast and tapinarof compared with topical corticosteroid regimens is unclear. (See 'Topical vitamin D analogs' below and 'Topical roflumilast' below and 'Tapinarof' below.)

Treatment with the topical retinoid tazarotene is an additional treatment option. However, because of the potential for skin irritation, we typically use tazarotene as an adjunct to topical corticosteroid therapy. In addition, combination therapy with a topical corticosteroid appears more effective than tazarotene monotherapy. (See 'Tazarotene' below.)

Plaques on the face, intertriginous areas, and genitals — For plaques in sites at greatest risk for corticosteroid-induced skin atrophy (face and intertriginous areas), we aim to minimize the duration and potency class of topical corticosteroid therapy. We still frequently begin treatment with a topical corticosteroid because of the efficacy, wide availability, and generally reasonable cost of topical corticosteroids (algorithm 1).

However, other topical therapies are effective for psoriasis and can be used as alternative initial treatments or corticosteroid-sparing treatments. Randomized trials support efficacy and tolerability of topical calcineurin inhibitors, topical vitamin D analogs, topical roflumilast, and topical tapinarof in intertriginous areas. (See 'Topical calcineurin inhibitors' below and 'Topical vitamin D analogs' below and 'Topical roflumilast' below and 'Tapinarof' below.)

The potential for treatment-induced skin irritation also influences treatment selection in sensitive skin sites. Because tazarotene can cause significant skin irritation, we do not typically use tazarotene for facial, intertriginous, and genital areas. (See 'Tazarotene' below.)

Whether combined treatment with a topical corticosteroid and vitamin D analog is superior to topical corticosteroid therapy alone for disease in facial, intertriginous, or genital sites is unclear.

Treatment options — Topical treatment options for chronic plaque psoriasis include topical corticosteroids, topical calcineurin inhibitors, topical roflumilast, topical tapinarof, topical tazarotene, and topical vitamin D analogs (table 1A).

Topical corticosteroids — Topical corticosteroids remain the mainstay of topical chronic plaque psoriasis treatment despite the availability of newer topical antipsoriatic agents [1]. Corticosteroids alter gene transcription, resulting in anti-inflammatory, antiproliferative, and immunosuppressive effects. (See 'Initial treatment selection' above and "Topical corticosteroids: Use and adverse effects", section on 'Mechanism of action'.)

●Selection – Selection of an appropriate topical corticosteroid begins with identification of an agent with sufficient potency to achieve satisfactory improvement and with an acceptable level of risk for adverse effects. The risk for adverse effects of topical corticosteroids increases with increasing drug potency, overuse, and occlusion. (See "Topical corticosteroids: Use and adverse effects", section on 'Adverse effects'.)

•Potency – The plaque site and plaque characteristics determine the most appropriate potency for initial therapy. In general, lower-potency agents are preferred for sites at greatest risk for skin atrophy [1].

-Most plaques in sites at low risk for corticosteroid-induced skin atrophy (eg, extremities, trunk, scalp) – Super high-potency to lower mid-potency topical corticosteroid (group 1 to 5 (table 2))

-Palmoplantar plaques and thick chronic plaques in sites at low risk for corticosteroid-induced skin atrophy (eg, extensor surfaces of extremities, back, scalp) – Super high-potency topical corticosteroid (group 1 to 4 (table 2))

-Plaques in sites at greatest risk for corticosteroid-induced skin atrophy (eg, face, intertriginous areas, and genitals) – Low-potency to least potent topical corticosteroid (group 6 or 7 (table 2))

The drug vehicle should also be acceptable to the patient. For patients who prefer a liquid oil vehicle for scalp treatment, fluocinolone oil is an alternative, albeit lower-potency, corticosteroid (table 2). (See 'Drug vehicle selection' above.)

●Administration – Topical corticosteroid therapy generally begins with twice-daily application to affected areas for two to four weeks. If used properly, chronic plaque psoriasis generally responds well to an appropriately selected corticosteroid. Initial signs of response often occur within the first few days, and clinically significant improvement typically occurs within four weeks.

When there is minimal improvement, we assess for reasons for treatment failure. Examples include an incorrect diagnosis, poor corticosteroid selection, and inadequate application. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Reasons for treatment failure'.)

For some plaques that improve with topical corticosteroids, daily treatment courses longer than four weeks are necessary for complete plaque clearance. Close clinician follow-up is prudent in this scenario. Because risk for adverse effects rises with increasing corticosteroid potency, we generally limit daily use of superpotent topical corticosteroids to four weeks, with longer treatment reserved for select cases (eg, thick plaques on the palms or soles) and when close clinical follow-up is feasible [1]. Alternatively, the clinician can incorporate other treatments. (See 'Treatment failure or intolerance' below.)

●Efficacy – Randomized trials support the efficacy of topical corticosteroid therapy [2-4].

•Psoriasis on the body – Findings from a 2013 systematic review of randomized trials evaluating topical therapies for plaque psoriasis support the efficacy of potent and very potent topical corticosteroids [3]. In contrast to the table (table 2), corticosteroids in the systematic review were classified as one of four potency levels (mild, medium, potent, or very potent) [3,5].

-In a meta-analysis of five trials (n = 515) that compared Investigator Assessment of Global Improvement (IAGI) from baseline after two to four weeks of treatment with a very potent corticosteroid (clobetasol propionate or halobetasol) to vehicle in patients with chronic plaque psoriasis on the body, very potent topical corticosteroid therapy was more effective (IAGI standardized mean difference [SMD] of -1.87, 95% CI -2.38 to -1.46, I² statistic = 78.7%) [3].

-In a meta-analysis of nine trials (n = 1867) that compared IAGI outcomes for chronic plaque psoriasis on the body after 3 to 12 weeks of treatment with one of six potent topical corticosteroids with outcomes after placebo, across all six treatments, potent topical corticosteroid therapy was more effective than vehicle (SMD of -1.00, 95% CI -1.18 to -0.82, I² statistic = 57.6%) [3].

•Scalp psoriasis – In a meta-analysis of four randomized trials assessing efficacy of topical corticosteroids specifically for scalp psoriasis (n = 1315), high- and very high-potency topical corticosteroids were more effective than vehicle for achieving "clearance" based on the Investigator Global Assessment (IGA; risk ratio 14.58, 95% CI 7.28-29.17) [4].

•Facial and intertriginous psoriasis – Studies assessing topical corticosteroid therapy for facial and intertriginous psoriasis are more limited [6]. In a trial in which 80 patients with intertriginous psoriasis were randomly assigned to treatment with betamethasone valerate 0.1% cream (a lower mid-potency [group 5] corticosteroid), calcipotriene 0.005% ointment, pimecrolimus 1% cream, or vehicle for four weeks, disease severity scores were reduced by 96, 62, 40, and 21 percent, respectively [7]. On statistical analysis, betamethasone valerate was more effective for reducing disease severity scores than pimecrolimus or vehicle, and calcipotriene was more effective than vehicle.

●Adverse effects – Examples of potential adverse effects from topical corticosteroids include cutaneous atrophy, acneiform eruptions, a cutaneous withdrawal syndrome, and hypothalamic-pituitary axis suppression (when used on large body surface areas [BSA] for long periods of time). The risks of cutaneous and systemic side effects from chronic topical corticosteroid use generally increase with increasing potency and treatment duration. Adverse effects are reviewed in detail separately. (See "Major adverse effects of systemic glucocorticoids" and "Topical corticosteroids: Use and adverse effects".)

Topical corticosteroid plus topical vitamin D analog — Combination therapy with a topical corticosteroid and topical vitamin D analog can be more effective than topical corticosteroid monotherapy. Potential disadvantages of combination treatment include higher treatment cost and increased complexity of the treatment regimen (for patients not using a fixed combination product (table 1A)). (See 'Topical vitamin D analogs' below.)

●Administration – Topical vitamin D analogs used for the treatment of psoriasis include calcipotriene (also known as calcipotriol), calcitriol, tacalcitol, and maxacalcitol. Calcipotriene is available as a combination product with betamethasone dipropionate (table 1A). Topical tacalcitol and maxacalcitol are not available in the United States.

Regimens for topical combination therapy vary. As in topical corticosteroid monotherapy, the topical corticosteroid should be selected based on the lesion site and characteristics. (See 'Topical corticosteroids' above.)

The fixed combination drug containing calcipotriene 0.005% and betamethasone dipropionate 0.064% is applied to affected areas once daily. For patients prescribed two separate products, we typically advise application of one product (eg, the topical vitamin D analog) in the morning and the other product (eg, topical corticosteroid) in the evening to avoid interactions that may reduce efficacy of the topical vitamin D analog. Acidic products can inactivate topical calcipotriene, and some topical corticosteroids may be acidic [8].

If used appropriately, clinical improvement generally occurs within two to four weeks.

An alternative initial regimen is a topical vitamin D analog applied twice daily on five consecutive days per week (eg, Monday to Friday) and a topical corticosteroid applied on two consecutive days per week (eg, Saturday and Sunday). Although this approach may also be effective [9], we tend to reserve this regimen for corticosteroid-sparing maintenance therapy. In our experience, daily topical corticosteroid therapy is less complicated for patients and yields faster improvement. (See 'Maintenance of response' below.)

●Efficacy – Data from randomized trials support that combined use of calcipotriene and a high-potency topical corticosteroid is effective and increases clinical response when compared with either agent used alone [2,3,10-12]. In addition, tolerability of calcipotriene may improve when used in conjunction with a topical corticosteroid [12,13].

•Psoriasis on the body (ie, trunk and extremities) – Findings from a systematic review of randomized trials assessing topical therapies for chronic plaque psoriasis on the body include [3]:

-In a meta-analysis of three trials (n = 1926) that compared IAGI outcomes for body psoriasis after two to eight weeks of combination treatment with calcipotriene plus betamethasone dipropionate with outcomes after betamethasone dipropionate monotherapy, calcipotriene plus betamethasone dipropionate was more effective (SMD -0.40, 95% CI -0.52 to -0.27, I² statistic = 41.8%) [3]. In a separate trial, calcipotriene plus clobetasol propionate was more effective than clobetasol propionate alone (SMD -0.69, 95% CI -1.22 to -0.15) [3].

-In a meta-analysis of 11 trials (n = 4791) that compared body psoriasis IAGI outcomes after two to eight weeks of treatment with a vitamin D analog alone with outcomes after combination treatment with a topical corticosteroid (primarily betamethasone dipropionate) and a topical vitamin D analog (primarily calcipotriol), topical vitamin D analog monotherapy was less effective overall (SMD 0.48, 95% CI 0.32-0.65, I² statistic = 86.9%) [3]. Some studies assessing lower-potency topical corticosteroids found equivalent efficacy.

•Scalp psoriasis – Combination therapy may also be more effective for scalp psoriasis [4].

-In a meta-analysis of four randomized trials (n = 2474) that compared scalp psoriasis IGA outcomes for topical corticosteroid and topical vitamin D analog combination therapy with topical corticosteroid monotherapy, combination therapy was slightly more effective for clearing psoriasis than topical corticosteroid monotherapy (relative risk 1.22, 95% CI 1.08-1.36, I² statistic = 0%).

-In a meta-analysis of four randomized trials (n = 2008) that compared IGA outcomes for combination therapy with treatment with a vitamin D analog alone, combination therapy was more effective for scalp psoriasis (relative risk 2.28, 95% CI 1.87-2.78, I² statistic = 0%).

•Facial and intertriginous psoriasis – Data on the efficacy of combination therapy for facial and intertriginous psoriasis are limited, and whether combination therapy is more effective than topical corticosteroid monotherapy is unclear [3].

The findings of a randomized trial (n = 408) suggest that combination therapy may be more effective than a topical vitamin D analog monotherapy. In the trial, which included patients with chronic plaque psoriasis involving both the face and other body areas, once-daily combined therapy with calcipotriene (at 25 mcg/g or 50 mcg/g) and hydrocortisone 1% ointment for eight weeks was more effective for reducing facial Psoriasis Area and Severity Index (PASI) scores and reaching absent or very mild facial disease on the IGA than once-daily treatment with calcipotriene alone [13]. Among patients treated with calcipotriene 50 mcg/g plus hydrocortisone, calcipotriene 25 mcg/g plus hydrocortisone, calcipotriene 50 mcg/g, and calcipotriene 25 mcg/g, absent or mild facial psoriasis occurred in 75, 70, 64, and 49 percent, respectively.

●Adverse effects – Potential adverse effects from combined treatment with a topical corticosteroid and vitamin D analog are similar to adverse effects of the individual therapies [14]. The inclusion of a potent topical corticosteroid limits the safety of long-term continuous use. However, the addition of a topical corticosteroid to vitamin D analog therapy may help to reduce risk for vitamin D analog-induced skin irritation [14,15]. (See 'Topical corticosteroids' above and 'Topical vitamin D analogs' below.)

Good tolerance of "as-required" use of the fixed combination product containing calcipotriene 0.005% and betamethasone dipropionate 0.064% over 52 weeks has been reported [14].

Tapinarof — Tapinarof is a topical aryl hydrocarbon receptor-modulating agent. The mechanisms of action for psoriasis may involve modulation of T helper type 17 (Th17) cytokines (eg, interleukin [IL] 17A and IL-17F), normalization of the skin barrier, and antioxidant activity. The US Food and Drug Administration (FDA) approved tapinarof 1% cream for the treatment of plaque psoriasis in adults in 2022 [16].

●Administration – Tapinarof 1% cream is applied to affected areas once daily. Clinical improvement is often evident within the first four to eight weeks of treatment [17].

●Efficacy – In two identical phase 3 trials (PSOARING 1 and PSOARING 2), a total of 1025 adults with chronic plaque psoriasis involving 3 to 20 percent of the total BSA were randomly assigned in a 2:1 ratio to either tapinarof 1% cream or vehicle applied once daily [17]. At week 12, patients in the tapinarof groups were more likely to achieve the primary endpoint of a Physician Global Assessment (PGA) score of 0 (clear) or 1 (almost clear) and at least a two-point decrease in the five-point PGA scale than patients in the placebo group (35.4 versus 6 percent [adjusted difference 29.4 percentage points; relative rate 5.8, 95% CI 2.9-11.5] in PSOARING 1 and 40.2 versus 6.3 percent [adjusted difference 33.9 percentage points; relative rate 6.1, 95% CI 3.3-11.4] in PSOARING 2). Rates of 75 and 90 percent improvement in the Psoriasis Area and Severity Index (PASI 75 and PASI 90, respectively) were also greater in the tapinarof groups than in the vehicle groups.

●Adverse effects – Local adverse effects appear to be the most common adverse effects of tapinarof. In the PSOARING 1 and PSOARING 2 trials, folliculitis, contact dermatitis, and headache occurred more frequently in the tapinarof groups than in the vehicle groups [17].

Topical roflumilast — Topical roflumilast is a phosphodiesterase 4 inhibitor. The FDA approved roflumilast 0.3% cream for the treatment of plaque psoriasis, including psoriasis in intertriginous areas, in people six years of age and older [18].

●Administration – Roflumilast 0.3% cream is applied to affected areas once daily. Clinical improvement often occurs within the first four weeks of treatment [19].

●Efficacy – In the DERMIS-1 (n = 439) and DERMIS-2 (n = 442) trials, adults and children (ages two years and older) with plaque psoriasis involving 2 to 20 percent of the BSA were randomly assigned in a 2:1 ratio to once-daily treatment with either roflumilast 0.3% cream or vehicle for eight weeks [19]. At week 8, patients treated with roflumilast were more likely to have IGA success (defined as clear or almost clear status plus at least a two-grade improvement from baseline on a five-point scale) than patients in the vehicle group (42.4 versus 6.1 percent [difference 39.6 percent, 95% CI 32.3-46.9 percent] in DERMIS-1 and 37.5 versus 6.9 percent [difference 28.9 percent, 95% CI 20.8-36.9 percent] in DERMIS-2).

Improvement in intertriginous psoriasis and pruritus was also greater in the roflumilast groups. For intertriginous psoriasis, IGA success in the roflumilast and vehicle groups occurred in 71.2 versus 13.8 percent (difference 66.5 percent, 95% CI 47.1-85.9 percent), respectively, in DERMIS-1 and 68.1 versus 18.5 percent (difference 51.6 percent, 95% CI 29.3-73.8 percent), respectively, in DERMIS-2.

●Adverse effects – In the DERMIS phase 3 trials, diarrhea was the most common reported treatment-emergent adverse event, occurring in 4 and 3 percent of patients in the roflumilast groups compared with no patients in the vehicle groups, and was often commensurate with higher BSA involvement [19]. In DERMIS-2, headache occurred in 4 percent of patients treated with roflumilast compared with 0.7 percent of patients in the vehicle group.

Topical vitamin D analogs — Topical vitamin D analogs for psoriasis include calcipotriene (also known as calcipotriol), calcitriol, tacalcitol, and maxacalcitol. Topical tacalcitol and maxacalcitol are not available in the United States.

Major mechanisms of action for topical vitamin D analogs may consist of inhibiting keratinocyte proliferation and stimulating keratinocyte differentiation [20-22]. Based on study of calcitriol, inhibition of T cell proliferation and other inflammatory mediators may also contribute [22].

●Administration – Topical vitamin D analogs are available as a variety of formulations and are usually applied twice daily when used as monotherapy (table 1A).

We typically use topical vitamin D analogs in conjunction with topical corticosteroids due to studies that suggest greater efficacy of combination therapy compared with vitamin D analog monotherapy [3,23,24]. However, use of a topical vitamin D analog alone is a reasonable alternative, particularly when there is a desire to avoid risk for adverse effects of long-term topical corticosteroid therapy. (See 'Topical corticosteroid plus topical vitamin D analog' above.)

Improvement with topical vitamin D analogs may be evident within the first two weeks of treatment, with continued improvement over subsequent weeks [25-30].

In addition, topical vitamin D analogs are often used for maintenance therapy. (See 'Maintenance of response' below.)

●Efficacy – Placebo-controlled randomized trials support the efficacy of topical vitamin D analogs [3,6,25-30]. In a meta-analysis of 20 randomized trials (n = 3771) that compared IAGI outcomes for body psoriasis after a 4- to 12-week course of any of seven topical vitamin D analogs with outcomes from placebo, topical vitamin D analogs were more effective than placebo (pooled SMD -0.95, 95% CI -1.17 to -0.74, I² statistic = 89%) [3]. In a randomized trial (n = 80) that compared outcomes for intertriginous psoriasis after four weeks of treatment with betamethasone valerate 0.1% cream, calcipotriene 0.005% ointment, pimecrolimus 1% cream, or vehicle, calcipotriene was more effective than vehicle [7]. Disease severity scores were reduced by 96, 62, 40, and 21 percent, respectively [7]. (See 'Topical corticosteroids' above.)

Trials that directly compare different vitamin D analogs are limited, contributing to uncertainty about the relative efficacy of these agents [3,6].

Whether topical vitamin D analogs are equivalent to or less effective than topical corticosteroid therapy is not clear. Outcomes from randomized trials comparing topical vitamin D analogs to topical corticosteroids vary, with interpretation of overall relative effect complicated by differences in study interventions, treatment sites, and regimens [3,4].

●Adverse effects – Examples of potential adverse effects of topical vitamin D analogs include skin irritation and hypercalcemia. Risk for hypercalcemia is considered low when these drugs are used appropriately [31,32]. For adults, we generally limit the amount of topical calcipotriene applied to no more than 100 g per week and the amount of topical calcitriol to no more than 200 mg per week [33,34]. The findings of one small trial (n = 75) suggest that calcitriol 3 mcg/g ointment may be less likely to induce skin irritation in sensitive areas (eg, face, hairline, retroauricular, or flexural areas) than calcipotriene 50 mcg/g ointment [35].

Topical calcineurin inhibitors — Topical calcineurin inhibitors, such as topical tacrolimus and topical pimecrolimus, exert anti-inflammatory effects through inhibiting calcineurin. When used for psoriasis, topical calcineurin inhibitors are primarily used for the treatment of facial, intertriginous, and genital areas.

●Administration – Topical tacrolimus 0.1% ointment and pimecrolimus 1% cream are typically applied to affected areas twice daily. Initial signs of improvement may occur as early as the first two weeks of treatment, with continued improvement expected over subsequent weeks.

●Efficacy – Randomized trials assessing topical calcineurin inhibitors for psoriasis are limited but suggest efficacy [36]. Examples of trials that have evaluated topical calcineurin inhibitors for facial or intertriginous psoriasis include [36,37]:

•In an eight-week trial, 167 patients with facial or intertriginous psoriasis were randomly assigned in a 2:1 ratio to twice-daily application of either tacrolimus 0.1% ointment or vehicle [38]. At week 8, more patients in the tacrolimus group achieved clear or almost clear status compared with patients in the vehicle group (65 versus 32 percent).

•In an eight-week trial, 57 patients with plaque psoriasis were randomly assigned to twice-daily application of either pimecrolimus 1% cream or vehicle to intertriginous plaques [39]. At week 8, more patients in the pimecrolimus group achieved clear or almost clear status compared with the patients in the vehicle group (71 versus 21 percent).

Although some studies have evaluated the relative efficacy of topical calcineurin inhibitors for facial or intertriginous psoriasis compared with other therapies, including studies suggesting greater efficacy of tacrolimus compared with calcitriol and lesser efficacy of pimecrolimus compared with betamethasone valerate, additional study is necessary to clarify relative efficacy [7,40].

●Adverse effects – Topical tacrolimus and pimecrolimus are generally well tolerated when used to treat facial and intertriginous psoriasis [38,39]. Transient skin burning, stinging, or itching sensations may occur at sites of application [36].

In 2006, the FDA placed a "boxed" warning on topical tacrolimus and pimecrolimus due to concerns about increased risk for malignancy; however, an association between these therapies and malignancy has not been proven. (See "Treatment of atopic dermatitis (eczema)", section on 'Topical calcineurin inhibitors'.)

Tazarotene — Tazarotene is a topical retinoid. The mechanisms of action for tazarotene include effects on keratinocyte differentiation and proliferation as well as downregulation of proinflammatory gene expression [1].

●Administration – Although tazarotene is available in multiple formulations, efficacy studies for psoriasis primarily involve tazarotene 0.05% cream, 0.1% cream, 0.05% gel, and 0.1% gel as well as halobetasol propionate-tazarotene 0.01%/0.045% lotion.

Tazarotene 0.05% or 0.1% cream or gel is applied to affected areas once daily in the evening. Because combining tazarotene with topical corticosteroid therapy may improve drug efficacy and tolerability [41], we typically use tazarotene in combination with daily or intermittent (eg, twice-weekly) topical corticosteroid therapy.

Initial signs of improvement from tazarotene may be evident as early as the first week of treatment, with further improvement over subsequent weeks [42]. (See 'Topical corticosteroids' above.)

The fixed combination product halobetasol propionate-tazarotene 0.01%/0.045% lotion is applied once daily.

We do not routinely use tazarotene for facial, intertriginous, or genital psoriasis because of the potential for skin irritation.

A short-contact regimen has also been utilized for tazarotene (eg, once-daily application for 20 minutes followed by washing off with water) to reduce skin irritation; however, efficacy data for this regimen are limited [43,44].

●Efficacy – Randomized trials support efficacy of tazarotene 0.05% and 0.1% cream and tazarotene 0.05% and 0.1% gel for plaque psoriasis [45,46].

•In two trials that randomly assigned a total of 1303 patients with plaque psoriasis to once-daily treatment with tazarotene 0.1% cream, tazarotene 0.05% cream, or vehicle, both tazarotene regimens were more effective than vehicle for achieving clinical success (defined as none, minimal, or mild features of plaque elevation, erythema, and scale) [45]. In one trial, week 12 success rates for tazarotene 0.1% cream, tazarotene 0.05% cream, and vehicle were 39, 42, and 25 percent, respectively. In the second trial, success rates were 51, 41, and 26 percent, respectively. Differences between the clinical success rates for the two tazarotene regimens generally were not statistically significant.

•In a trial that randomly assigned 324 patients with plaque psoriasis to once-daily treatment with tazarotene 0.1% gel, tazarotene 0.05% gel, or vehicle, both tazarotene regimens were more effective than vehicle for reducing the overall severity score for three clinical signs of psoriasis (plaque elevation, erythema, scaling) [46]. At week 12, target lesion treatment success rates (defined as at least 50 percent improvement in a disease severity score) for tazarotene 0.1% gel, tazarotene 0.05% gel, and vehicle were 70, 59, and 35 percent, respectively.

Randomized trials also support efficacy of the fixed combination product halobetasol propionate-tazarotene 0.01%/0.045% lotion.

•In two trials that randomly assigned a total of 418 patients with plaque psoriasis (in a 2:1 ratio) to twice-daily application of either halobetasol propionate-tazarotene 0.01%/0.045% lotion or vehicle [47], week 8 treatment success (defined as at least two-grade improvements in erythema, plaque elevation, and scale in the five-point IGA scores and a score of clear or almost clear) occurred in 36 and 45 percent of patients treated with the combination drug in the two trials. In the placebo groups, only 7 and 13 percent of patients achieved this endpoint, respectively.

A few studies suggest that combining topical tazarotene with topical corticosteroids improves efficacy and tolerability of tazarotene [48-50].

•In a trial, 599 patients with chronic plaque psoriasis were randomly assigned to treatment with the fixed combination drug tazarotene-betamethasone propionate 0.05%/0.05% cream once daily, tazarotene 0.05% gel once daily, or betamethasone propionate cream 0.05% twice daily [48]. At week 6, PASI 75 rates for the combination product, betamethasone propionate, and tazarotene groups were 45, 35, and 19 percent, respectively, with a statistically significant difference only between the combination product and tazarotene groups. Skin irritation occurred less frequently in the combination group than in the tazarotene group (13 versus 29 percent).

An advantage of tazarotene may be persistent benefit after stopping treatment [48,51,52]. In a randomized trial that assessed efficacy of a 12-week course of tazarotene 0.1% gel, tazarotene 0.05% gel, or fluocinonide 0.05% cream, the tazarotene and fluocinonide formulations had similar efficacy at week 12, but tazarotene 0.1% gel was associated with better maintenance of response than fluocinonide during the 12 weeks after cessation of treatment [51]. In the trial that compared fixed combination drug tazarotene-betamethasone propionate 0.05%/0.05% cream once daily, tazarotene 0.05% gel once daily, or betamethasone cream 0.05% twice daily, patients treated with the combination product had lower relapse eight weeks after treatment cessation than patients in the betamethasone group (11 versus 30 percent) [48].

●Adverse effects – Local skin reactions (eg, pruritus, burning sensations, erythema) are the most common adverse effects of tazarotene. Tazarotene should not be used during pregnancy.

Maintenance of response — Chronic plaque psoriasis plaques typically recur after cessation of treatment. After achievement of satisfactory response, treatment can either be stopped with a plan to restart treatment upon plaque recurrence or the patient can begin a maintenance regimen. We use maintenance therapy frequently, particularly for plaques with a history of rapid plaque recurrence and for plaques that are particularly bothersome for the patient (eg, symptomatic or located in cosmetically sensitive areas).

●Maintenance with topical corticosteroids – For patients treated with a regimen containing a topical corticosteroid, reducing long-term corticosteroid exposure to minimize risk for local and systemic adverse effects is a major consideration in the maintenance regimen.

For plaques in sites at low risk for corticosteroid-induced skin atrophy, our typical maintenance regimen consists of intermittent treatment with the previously effective topical corticosteroid (eg, application twice daily on two consecutive days per week [eg, weekends]). Higher rates of prolonged remission or maintenance of improvement have been reported in patients who continued high-potency topical corticosteroid therapy for two days per week after responding to daily therapy compared with patients who stopped therapy [2,53,54].

•Addition of a vitamin D analog – Adding a vitamin D analog to a topical corticosteroid maintenance regimen may offer additional benefit [2,10]. In one trial, 40 patients with psoriasis that responded to two weeks of once-daily treatment with calcipotriene 0.005% ointment and halobetasol 0.05% ointment were randomly assigned to a regimen of halobetasol twice daily on weekends and calcipotriene twice daily on weekdays or a regimen of halobetasol twice daily on weekends and a placebo ointment on weekdays. At six months, maintenance of remission was present in 76 and 40 percent of patients, respectively [10]. (See 'Topical vitamin D analogs' above.)

Our typical regimen for combination maintenance therapy consists of application of the topical vitamin D analog twice daily Monday to Friday and application of the corticosteroid twice daily on weekends. For patients who achieve sustained maintenance with this regimen, further reductions in the frequency of application of the corticosteroid can be attempted.

•Vitamin D analog alone – Maintenance therapy with a vitamin D analog alone can be sufficient for some patients. However, a small randomized trial that followed 38 patients after an initial response to daily therapy with calcipotriene 0.005% ointment and clobetasol 0.05% foam found a nonstatistically significant trend toward better maintenance of response or continued improvement after six months with weekday use of calcipotriene ointment plus weekend use of clobetasol propionate foam compared with weekday use of calcipotriene alone [55]. (See 'Topical vitamin D analogs' above.)

●Maintenance regimens with other therapies – Compared with topical corticosteroids, maintenance regimens for disease responding to other topical psoriasis therapies are less established. In general, the frequency of application is reduced, as tolerated, to the lowest frequency required to maintain improvement.

For disease successfully treated with topical corticosteroids, clinical experience suggests nonsteroidal therapies other than topical vitamin D analogs may also be beneficial for maintaining improvement and reducing exposure to topical corticosteroids.

Treatment failure or intolerance — Treatment adjustments may be necessary when there is an insufficient response to a topical regimen or the regimen is not tolerable or feasible.

Assessing reasons for treatment failure — Prior to adjusting therapy, factors that may contribute to inefficacy of topical therapy should be considered. Examples include incorrect diagnosis, suboptimal treatment selection, and inadequate administration of therapy. These concepts are reviewed separately. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Reasons for treatment failure'.)

Subsequent treatment selection — Selection of next-line treatment for chronic plaque psoriasis involves consideration of the patient's preferences for therapy. Continued trials of topical agents may be preferable for patients who prefer topical treatment. Targeted phototherapy and systemic therapy are options for patients who prefer a different approach to therapy or for whom satisfactory improvement with topical therapy alone is not feasible.

●Adjusting topical corticosteroid therapy – For disease treated with topical corticosteroids, adjusting the administration of topical therapy may be beneficial. Options that may augment response include selecting a topical corticosteroid of greater potency (table 2) or increasing potency through applying the topical corticosteroid under an occlusive dressing [56]. (See "Topical corticosteroids: Use and adverse effects", section on 'Potency'.)

A disadvantage of these options is increased risk for corticosteroid adverse effects. Thus, we use these measures less frequently for sites at greatest risk for adverse effects of corticosteroids (eg, face, intertriginous areas).

Intralesional injection of corticosteroids is an additional option for local corticosteroid therapy that may be beneficial for thick psoriasis plaques in sites at low risk for corticosteroid-related local adverse effects. (See 'Intralesional corticosteroid injections' below.)

●Adding or switching therapy – We typically consider adding or switching therapy when a topical regimen is insufficiently effective despite appropriate use for four to eight weeks. Options include adjusting the topical regimen or proceeding to phototherapy or systemic therapy.

•Topical therapy – Some patients initially treated with a single topical therapy may benefit from proceeding to combination topical therapy. Combined therapy with a topical corticosteroid and topical vitamin D analog can be more effective than either monotherapy with these drugs. (See 'Topical corticosteroid plus topical vitamin D analog' above.)

Switching to a topical treatment with a different mechanism of action (eg, switching from a topical calcineurin inhibitor to a topical corticosteroid) is an additional option.

•Targeted phototherapy or systemic therapy – Targeted phototherapy allows for the delivery of therapeutic light to specific skin areas and is often used in conjunction with topical therapy. (See 'Targeted phototherapy' below.)

Patients with disease that cannot be adequately managed with topical therapy or phototherapy (eg, based on response or feasibility) are candidates for systemic therapy. (See 'Intralesional, ultraviolet light, and systemic therapies' below.)

INTRALESIONAL, ULTRAVIOLET LIGHT, AND SYSTEMIC THERAPIES — 

For patients with limited areas of psoriasis who are candidates for topical therapy, we primarily use intralesional therapy, targeted phototherapy, and systemic therapy when factors such as insufficient response, adverse effects, impracticality, or patient preference support a different approach to treatment. However, these therapies may also be appropriate for initial treatment in select cases. Selection among these therapies involves consideration of the clinical presentation, patient characteristics, and the patient's preferences for therapy. (See 'Subsequent treatment selection' above.)

Intralesional corticosteroid injections — Intralesional injection of corticosteroids may be beneficial for thick chronic psoriasis plaques that respond insufficiently to topical therapy.

●Administration – The approach to intralesional corticosteroid therapy for psoriasis is not standardized. Our typical regimen consists of triamcinolone acetonide injections administered every four to six weeks based on response [1]. Clinically significant improvement is expected within one to three treatments.

Concentrations of triamcinolone acetonide used for chronic plaque psoriasis generally range from 2.5 to 20 mg/mL. The appropriate concentration is selected based on the treatment site and lesion characteristics, with the highest concentrations reserved for thick lesions in sites at lowest risk for corticosteroid-induced skin atrophy. Because of risk for systemic adverse effects, we typically limit the total dose of triamcinolone acetonide to no more than 40 mg per month. (See "Intralesional corticosteroid injection", section on 'Dosing' and "Intralesional corticosteroid injection", section on 'Systemic adverse effects'.)

The potential for hypopigmentation is an additional adverse effect that should be considered prior to intralesional injection. When it occurs, hypopigmentation is most noticeable in patients with highly pigmented skin (eg, skin phototypes IV to VI (table 3)). (See "Intralesional corticosteroid injection", section on 'Local adverse effects'.)

The procedure and precautions for intralesional injection of corticosteroids are reviewed separately. (See "Intralesional corticosteroid injection".)

●Efficacy – Although intralesional corticosteroid injection is generally considered effective, efficacy data are limited [57,58].

Intralesional corticosteroid therapy appeared beneficial in a study in which 24 patients with plaque psoriasis received intralesional injections of triamcinolone acetonide (at 10 mg/mL) on one psoriatic plaque and intralesional injections of fluorouracil (at 50 mg/mL) on a contralateral plaque every two weeks for a total of three sessions [58]. After 12 weeks, the percentage improvement in a psoriasis severity index score was greater in sites treated with triamcinolone than with fluorouracil (89 versus 67 percent).

●Adverse effects – Examples of potential adverse effects of intralesional corticosteroid injection include skin atrophy, hypopigmentation, and adrenal suppression. Adverse effects are reviewed in greater detail separately. (See "Intralesional corticosteroid injection", section on 'Adverse effects and pitfalls'.)

Targeted phototherapy — Phototherapy involves treatment with various ultraviolet light-emitting devices. For limited disease, targeted phototherapy is often favored over booth phototherapy, as it allows for the delivery of therapeutic light to localized areas of involved skin and spares exposure of uninvolved skin areas. (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy".)

The major forms of targeted phototherapy are targeted ultraviolet B (UVB) phototherapy (308 nm excimer laser, 308 nm excimer light, or 311 to 313 nm narrowband ultraviolet B [NBUVB] light) and topical psoralen plus ultraviolet A (PUVA) photochemotherapy. (See "Targeted phototherapy".)

The excimer laser is the most common mode utilized for plaque psoriasis. The use and availability of PUVA photochemotherapy has decreased due to easier administration of UVB phototherapy, long-term risks of PUVA, and the availability of other effective psoriasis therapies.

●Administration – Targeted phototherapy is typically administered two to three times per week at the start of treatment.

The time to response varies. With the excimer laser, clinically significant improvement is often evident within the first few weeks of treatment. (See "Targeted phototherapy", section on 'Dosing and treatment regimens'.)

After achievement of a satisfactory response, treatment can be stopped and restarted upon disease recurrence, or the frequency of treatment can be tapered to a maintenance regimen.

Targeted phototherapy is often used in conjunction with topical therapy. However, because ultraviolet light exposure can degrade topical vitamin D analogs, topical vitamin D analogs should be applied after, rather than immediately prior to, phototherapy.

Contraindications for phototherapy are reviewed separately. (See "Targeted phototherapy", section on 'Contraindications'.)

●Efficacy – Randomized trial data for targeted phototherapy are limited. A systematic review and meta-analysis of clinical studies and case series assessed targeted phototherapy for plaque psoriasis. In the analysis of 15 studies assessing forms of targeted UVB phototherapy (excimer laser, excimer light, or NBUVB), the pooled weighted estimate of the percentage of patients achieving at least a 75 percent reduction in the disease severity score was 61 percent (95% CI 50-71 percent) [59]. Pooled estimates of efficacy specifically for topical PUVA, excimer laser, excimer light, and targeted NBUVB phototherapy were 77, 70, 59, and 49 percent, respectively.

An advantage of the excimer laser over booth NBUVB phototherapy is that excimer treatment is directed only to the psoriasis plaques and not to the normal skin. Because the psoriasis plaques are less sensitive to burning than normal skin, higher initial doses of UV light may be given with the excimer laser (doses that would burn normal skin), resulting in faster improvement. In a small study that compared the effects of excimer laser on one target lesion with booth NBUVB on another target lesion in six patients with chronic plaque psoriasis, complete clearance occurred within 8 to 10 treatments with the excimer laser compared with 29 to 33 treatments for booth NBUVB [60]. (See "Targeted phototherapy", section on 'Targeted versus full-body phototherapy'.)

Although topical therapy is commonly used in conjunction with phototherapy, there is some uncertainty about whether combination therapy improves outcomes. Studies investigating whether use of a vitamin D analog augments the response to targeted UVB phototherapy have yielded conflicting results [61]. Some studies suggest benefit of UVB phototherapy combined with tazarotene [62-64].

Other studies have compared outcomes from the excimer laser with outcomes of other light-based therapies not in routine use for psoriasis [65,66].

●Adverse effects – Potential adverse effects of targeted phototherapy include erythema, blistering, and hyperpigmentation. Use of an appropriate dosing protocol minimizes the risk for erythema and blistering. The impact of targeted phototherapy on risk for photoaging and skin cancer is unclear but is expected to be small, as only localized affected areas are treated. (See "Targeted phototherapy", section on 'Short- and long-term adverse effects'.)

Systemic therapy — Systemic therapy is primarily reserved for disease considered less amenable to topical therapy and disease that responds insufficiently to topical therapy. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Selecting the primary mode of therapy'.)

Consideration of drug safety and tolerability is of particular importance when treating limited disease. The selection of systemic therapy is reviewed in detail separately. (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy".)

Although efficacy of established systemic psoriasis therapies for limited disease is expected, most trials have been performed in patients with extensive disease. Oral apremilast was effective for patients with limited skin involvement in a randomized trial limited to patients with mild to moderate chronic plaque psoriasis based on ≤15 percent body surface area (BSA) involvement, Physician Global Assessment (PGA) ratings, and Psoriasis Area and Severity Index (PASI) scores [67]. (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy", section on 'Apremilast'.)

ADJUNCTIVE INTERVENTIONS — 

Common adjunctive interventions include emollients, salicylic acid, and tar shampoo.

Emollients — Daily skin moisturization may help to reduce symptoms of pruritus or skin discomfort and may help support maintenance of improvement from other treatments [68].

In our experience, ointments such as petroleum jelly or thick creams are most beneficial, especially when applied immediately after a bath or shower. Lotions are an alternative for patients who prefer to avoid ointments or thick creams.

Salicylic acid — Salicylic acid is a keratolytic agent that may be useful as an adjunct to topical corticosteroid therapy. Salicylic acid may reduce scale and augment penetration of other therapies [69-72].

Salicylic acid is available in a wide variety of formations. In our experience, body washes, shampoos, or emollients with salicylic concentrations ranging from 2 to 6 percent can be beneficial. However, the low pH of salicylic acid may impact the efficacy of some other topical therapies (eg, inactivation of topical vitamin D analogs).

In a trial that randomly assigned 408 patients with plaque psoriasis to treatment with either mometasone furoate 0.1% plus salicylic acid ointment or mometasone furoate 0.1% ointment alone for 21 days, combination therapy was associated with greater improvement in total disease and scaling scores [72].

Tar — Topical coal tar is a longstanding psoriasis therapy that appears to have anti-inflammatory and antiproliferative effects [73]. The precise mechanism of action of tar is not known but may involve aryl hydrocarbon receptors [74].

Limited efficacy data and the development of other treatment options for chronic plaque psoriasis has reduced the use of tar products for treatment. Our use of tar is primarily limited to use of coal tar shampoo as an adjunctive therapy for scalp psoriasis and scalp sebopsoriasis (overlapping scalp seborrheic dermatitis and psoriasis). Patients can use a tar shampoo (containing 0.5% to 1% coal tar) daily (or less frequently in accordance with a feasible hair washing frequency). Tar shampoos are generally applied and left in place for 5 to 10 minutes before rinsing.

Tar products are also commercially available in other formulations (eg, ointment, solution, foam) and as compounded preparations. Such preparations are generally applied once daily. (See "Coal tar: Drug information".)

Tar products have the potential to stain skin, hair, or clothing. Some patients may also find the odor of tar products unpleasant.

Anthralin — Topical anthralin (also known as dithranol) is no longer commonly used for chronic plaque psoriasis because of the availability of more effective and well-tolerated agents [3,75,76]. The mechanism of action of anthralin in psoriasis is not well understood but may involve anti-inflammatory effects and normalization of keratinocyte differentiation [77].

Anthralin cream is no longer commercially available in many settings. In the United States, anthralin is commercially marketed only as a 1% shampoo. Anthralin cream may be available through compounding pharmacies. Anthralin often causes skin irritation, temporary stains on skin, and permanent statins on clothing.

PROGRESSION TO DISEASE LESS AMENABLE TO TOPICAL THERAPY — 

The approach to disease that presents as or progresses to a presentation that is less amenable to topical therapy is reviewed separately. (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy".)

SOCIETY GUIDELINE LINKS — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Psoriasis".)

SUMMARY AND RECOMMENDATIONS

●Overview – Chronic plaque psoriasis is a common inflammatory disorder characterized by inflamed, well-demarcated plaques on the skin (picture 1A-H). Treatments for chronic plaque psoriasis include topical therapies, phototherapy, and systemic therapies (table 1A-B). (See "Chronic plaque psoriasis in adults: Treatment of disease requiring phototherapy or systemic therapy", section on 'Introduction'.)

●Impact of clinical presentation on treatment selection – Multiple factors influence treatment selection, such as the extent and location of skin involvement, the presence of complications or comorbidities, the feasibility of adequate administration of therapy, patient preference, and treatment availability (algorithm 1). Relative safety and a lack of need for specialized equipment or clinician administration are the major advantages of topical treatment. (See "Chronic plaque psoriasis in adults: Overview of management", section on 'Selecting the primary mode of therapy'.)

●Disease extent and location appropriate for topical therapy – In general, initial treatment with topical agents alone is most feasible for disease involving limited body surface area (BSA). Patients with extensive disease or disease in difficult-to-treat sites may benefit from phototherapy or systemic therapy. Topical therapy is often used as an adjunct to these therapies. (See 'Identifying disease appropriate for topical therapy' above and "Chronic plaque psoriasis in adults: Overview of management", section on 'Extent and location of skin involvement'.)

●Supporting optimal use of topical therapy – Long-term adherence to topical therapy can be challenging. Factors that may help to support successful use of topical therapy include an appropriate drug vehicle, a tolerable drug regimen, adequate patient counseling, and close clinician follow-up. (See 'Supporting efficacy of topical therapy' above.)

●Initial treatment

•Initial therapy for nonintertriginous, nonfacial, nongenital plaques – For nonintertriginous, nonfacial, nongenital plaques that will be treated topically, we suggest a topical corticosteroid for initial treatment rather than other topical therapies (algorithm 1) (Grade 2C). Topical corticosteroids are effective, widely available, and can be relatively low in cost. The appropriate corticosteroid potency is selected based on plaque site and plaque characteristics. We typically treat these sites with a super high- to lower mid-potency topical corticosteroid (group 1 to 5 (table 2)). (See 'Topical corticosteroids' above.)

Combination therapy with a topical corticosteroid and topical vitamin D analog can be more effective than topical corticosteroid monotherapy and is a reasonable alternative to topical corticosteroid monotherapy. Potential disadvantages of this approach are higher cost and increased complexity of the treatment regimen. Use of a fixed combination product can simplify the treatment regimen. (See 'Topical corticosteroid plus topical vitamin D analog' above.)

Reasonable alternatives for patients who prefer to avoid or cannot tolerate topical corticosteroid therapy include a vitamin D analog alone, tazarotene, topical roflumilast, and topical tapinarof. (See 'Treatment options' above.)

•Initial therapy for facial, intertriginous, or genital plaques – We suggest a low-potency topical corticosteroid for initial treatment rather than other topical therapies (algorithm 1) (Grade 2C). Topical corticosteroids are effective, widely available, and can be relatively low in cost. However, continuous, long-term use of topical corticosteroids in these sites should be avoided because of risk for corticosteroid-induced skin atrophy. (See 'Topical corticosteroids' above.)

Reasonable alternatives for patients who prefer to avoid or cannot tolerate topical corticosteroid therapy include topical calcineurin inhibitors, topical vitamin D analogs, topical roflumilast, and topical tapinarof. (See 'Treatment options' above.)

●Precautions for topical corticosteroid therapy – Patients treated with topical corticosteroids should be followed for the development of adverse effects, such as cutaneous atrophy. We have a low threshold for incorporating other therapies when frequent or long-term corticosteroid therapy is required to achieve a satisfactory response, particularly for skin sites at greatest risk for corticosteroid-induced atrophy (eg, face, intertriginous areas). (See 'Topical corticosteroids' above.)

●Maintenance of response – Chronic plaque psoriasis often recurs after treatment cessation. After achievement of a satisfactory response, options include restarting treatment upon plaque recurrence or implementing a maintenance regimen. Maintenance regimens typically involve intermittent use of a topical corticosteroid and/or topical corticosteroid-sparing therapies. (See 'Maintenance of response' above.)

●Treatment failure – An inadequate response to topical therapy should prompt assessment for reasons for treatment failure. Examples include incorrect diagnosis, suboptimal treatment selection, inadequate administration of topical therapy, and resistant disease. (See 'Assessing reasons for treatment failure' above and "Chronic plaque psoriasis in adults: Overview of management", section on 'Reasons for treatment failure'.)

When switching therapy or adding another therapy appears necessary, patient preference heavily influences the selection of subsequent therapy. Options for limited disease include trials of alternative topical regimens, intralesional corticosteroid injections, phototherapy, and systemic therapy (algorithm 1). (See 'Treatment failure or intolerance' above and 'Intralesional, ultraviolet light, and systemic therapies' above.)