Intertrigo

INTRODUCTION — Intertrigo, or intertriginous dermatitis, is a common inflammatory condition of skin folds characterized by moist erythema, malodor, weeping, pruritus, and tenderness (picture 1A-D). Initiating factors include moisture and friction associated with an absence of air circulation in deep skin folds. In addition, candidal or bacterial infection may initiate or aggravate intertrigo.

The diagnosis is usually straightforward and based upon the clinical findings. Treatment is rapidly effective in the majority of patients. However, the disease typically recurs if initiating and exacerbating factors are not eliminated.

The clinical features, diagnosis, and management of intertrigo will be reviewed here. Intertrigo involving the diaper area of young children and other forms of diaper dermatitis are reviewed in detail separately. (See "Diaper dermatitis".)

EPIDEMIOLOGY AND RISK FACTORS — Intertrigo can affect individuals of all ages, sexes, and socioeconomic backgrounds and is predisposed by the chronic presence of moisture within deep skin folds. It is most common in bedridden or debilitated older adults and infants because of immobility and minimal aeration of intertriginous areas.

Data from studies of nursing home and hospitalized patients support the frequent occurrence of intertrigo in older adults and seriously ill populations. Almost 10 percent of patients receiving nursing care at home and 7 percent of patients in nursing homes had intertrigo in a study of data from over 40,000 patients from four cross-sectional studies in the Netherlands [1]. Moreover, in a retrospective study of 417 patients admitted to a community hospital in South Carolina over a three-year period, the mean prevalence of intertrigo was 40 percent [2].

Cutaneous infections, particularly Candida infection, may initiate or exacerbate intertrigo.

Additional risk factors include obesity, incontinence, poor hygiene, hyperhidrosis, and immune deficiencies that increase risk for skin infections (particularly Candida infection), such as in diabetes mellitus, HIV infection, and malnutrition. Erosio interdigitalis blastomycetica, a variant of candidal intertrigo that occurs in web spaces of the digits, typically occurs in association with frequent wet work involving the hands (eg, dishwashing) or hyperhidrosis. (See "Susceptibility to infections in persons with diabetes mellitus".)

PATHOGENESIS — The pathophysiologic basis of intertrigo is characterized by a variety of predisposing factors that often coincide to promote inflammation within deep skin folds, including humidity, friction, and infection. Rubbing of moist skin against moist skin leads to maceration and denudes the stratum corneum, exposing Langerhans cells to environmental pathogens that stimulate an immune reaction.

Fungal or bacterial infection or colonization of the skin may contribute to intertrigo through the initiation of innate or acquired immunity-mediated inflammatory cascades. Candidal infection is common in intertrigo and may exacerbate or induce its development. Secondary bacterial infection may also occur, particularly in areas of excoriated skin. Seborrheic dermatitis, an inflammatory disorder in which fungi in the genus Malassezia are thought to play a role, may present with findings consistent with intertrigo. (See "Susceptibility to infections in persons with diabetes mellitus".)

Additional exacerbating factors for intertrigo include irritant and allergic contact dermatitis. The chronically irritated skin of intertrigo increases susceptibility for these disorders. Common causes of allergic contact dermatitis include fragrances in perfumes, colognes, and moisturizers; preservatives in moisturizers and diaper wipes (eg, methylchloroisothiazolinone [MCI] and methylisothiazolinone [MI]); and topical medications (including topical corticosteroids). Irritant contact dermatitis may result from urine, feces, soaps, detergents, and other irritants that are not thoroughly rinsed from skin in involved areas. (See "Common allergens in allergic contact dermatitis".)

CLINICAL PRESENTATION — Intertrigo can occur in any area where skin opposes skin. The hallmark clinical finding is a moist, red or red-brown, beefy, homogenous patch within skin folds (picture 1A-D). Most cases of intertrigo occur in the deep folds of the groin, though it is also common in the axillary area, inframammary area, umbilicus, and under the panniculus. Neck fold involvement is common in infants and may also occur in individuals with torticollis (picture 2). The antecubital fossae and popliteal fossae can be involved in patients with limb contractures. Erythematous satellite papules and pustules suggest candidal involvement (picture 3).

Patients with intertrigo may complain of burning, tenderness, pruritus, and/or a malodorous discharge within affected areas. When fissuring is present, the involved areas can be especially painful. Scratching can lead to excoriations and bruising.

Erosio interdigitalis blastomycetica (candidal intertrigo of the finger or toe web spaces) presents with moist erythema and fissuring in the deepest part of the web space (picture 1D). On the feet, it usually involves the third and fourth or fourth and fifth web spaces. Despite the name, there is no relationship to infection with the Blastomycetes fungal organism.

Intertrigo may occur in association with seborrheic dermatitis in infants and adults (picture 4A-B). These patients usually exhibit erythema and scale in other areas characteristic for seborrheic dermatitis, such as the face, retroauricular skin, and scalp. (See "Seborrheic dermatitis in adolescents and adults", section on 'Clinical manifestations' and "Cradle cap and seborrheic dermatitis in infants", section on 'Clinical manifestations'.)

CLINICAL COURSE — Intertrigo typically persists if measures are not taken to eliminate contributory factors. With appropriate management, intertrigo usually clears rapidly. Secondary infection and cellulitis are potential complications of persistent intertrigo. (See 'Treatment' below.)

DIAGNOSIS — Intertrigo typically can be diagnosed based upon the physical examination. Supportive findings include erythematous, moist patches limited to intertriginous skin. Findings that should prompt consideration of other disorders include vesicles, bullae, extensive erosions, and vegetative plaques. (See 'Differential diagnosis' below.)

A full skin examination is helpful for identifying other sites of involvement as well as detecting abnormalities on nonintertriginous skin or nails that suggest other disorders. Examination with a Wood's lamp is helpful for distinguishing intertrigo from erythrasma (picture 5). (See 'Differential diagnosis' below.)

Although not required in patients who have a clinical picture consistent with intertrigo, candidal involvement (suggested by the presence of satellite papules and pustules) may be confirmed with a potassium hydroxide (KOH) preparation of skin scrapings from a satellite pustule or skin fold (picture 6). A KOH preparation is also helpful for identifying patients with tinea cruris (caused by dermatophyte fungi) rather than intertrigo; suggestive findings for tinea cruris are erythematous patches with partial central clearing and a slightly elevated, erythematous border. An alternative to a KOH preparation is a fungal culture. (See "Office-based dermatologic diagnostic procedures", section on 'Potassium hydroxide preparation' and "Dermatophyte (tinea) infections", section on 'Tinea cruris' and 'Differential diagnosis' below.)

A bacterial culture should be obtained for patients with signs of secondary bacterial infection (purulence, crusting, pain). Perianal involvement in children should raise concern for perianal streptococcal infection.

Skin biopsies are not usually indicated and are reserved for patients in whom the diagnosis is uncertain and a disorder requiring a biopsy diagnosis is in the differential diagnosis (eg, Hailey-Hailey disease or pemphigus vegetans). (See 'Differential diagnosis' below.)

DIFFERENTIAL DIAGNOSIS — A variety of other inflammatory disorders can present with intertriginous erythema. Disorders commonly in the differential diagnosis include psoriasis, tinea cruris, erythrasma, and contact dermatitis:

●Inverse psoriasis – Inverse psoriasis is a variant of psoriasis characterized by the development of well-demarcated, shiny plaques on intertriginous skin (picture 7) [3,4]. There is minimal to no overlying scale. Common sites include the groin, axillae, and inframammary skin. Friction and maceration are postulated to contribute to the development of intertriginous manifestations in patients with psoriasis through the Koebner phenomenon (development of new skin disease lesions in sites of cutaneous trauma) [3]. The identification of other cutaneous or nail manifestations of psoriasis (eg, psoriatic plaques, nail pits, onychomycosis) aids in distinguishing inverse psoriasis from intertrigo. (See "Psoriasis: Epidemiology, clinical manifestations, and diagnosis", section on 'Inverse (intertriginous) psoriasis'.)

●Tinea cruris – Tinea cruris is a dermatophyte infection involving the groin, proximal medial thighs, perineum, or buttocks. The classic presentation consists of a centrifugally expanding, erythematous patch with partial central clearing and a slightly elevated, sharply demarcated border (picture 8). Concomitant tinea pedis is common. A potassium hydroxide preparation demonstrating septate hyphae characteristic of dermatophytes confirms the diagnosis (picture 9). (See "Dermatophyte (tinea) infections", section on 'Tinea cruris'.)

●Erythrasma – Erythrasma is a cutaneous corynebacterial infection that typically presents as macerated, scaly plaques between the toes or as an intertriginous eruption of erythematous to brown patches or thin plaques with fine scale (picture 10A-C). The moist maceration of intertrigo is typically absent in areas other than the feet. Examination of erythrasma with a Wood's lamp demonstrates coral-red fluorescence and is useful for distinguishing erythrasma from intertrigo. (See "Erythrasma".)

●Allergic contact dermatitis – Allergic contact dermatitis to substances that come in contact with intertriginous skin, such as methylisothiazolinone used as a preservative in diaper "wet" wipes, can mimic intertrigo or represent a secondary complicating factor in patients with intertrigo (picture 11A-C). Elimination of the allergen is required for resolution [5]. The patient history is helpful for diagnosis. In addition, unlike intertrigo, the dermatitis usually extends out beyond the intertriginous skin. (See "Clinical features and diagnosis of allergic contact dermatitis" and "Common allergens in allergic contact dermatitis".)

Less common disorders in the differential diagnosis are Hailey-Hailey disease, pemphigus vegetans, malignant intertrigo, and Langerhans cell histiocytosis:

●Hailey-Hailey disease – Hailey-Hailey disease, also known as benign familial pemphigus, is a rare genetic disorder that presents with blistering, erosions, maceration, and frequent secondary infection primarily on flexural skin. Patients often present with large, macerated, exudative plaques with superficial erosions and crusting (picture 12A-C). Vegetative, malodorous plaques with painful fissures may also occur. Many patients also have longitudinal white bands on the nails. A skin biopsy is needed to confirm the diagnosis. (See "Hailey-Hailey disease (benign familial pemphigus)".)

●Pemphigus vegetans of Hallopeau – Pemphigus vegetans of Hallopeau is a variant of pemphigus that presents with vegetating plaques on intertriginous skin (picture 13A-B) [6]. Skin biopsies for routine histologic examination and direct immunofluorescence are necessary to confirm the diagnosis. Direct immunofluorescence testing reveals intercellular deposition of immunoglobulin G (IgG) in the epidermis. (See "Pathogenesis, clinical manifestations, and diagnosis of pemphigus", section on 'Pemphigus vulgaris'.)

●Malignant intertrigo – Malignant intertrigo is a distinct subset of toxic erythema of chemotherapy affecting the intertriginous area [7]. Malignant intertrigo is more painful and tender than classic intertrigo and is not associated with satellite papules or pustules at the periphery. It has been described in association with a variety of chemotherapies [8].

●Langerhans cell histiocytosis – Langerhans cell histiocytosis is a rare, histiocytic disorder that most commonly occurs in young children but may also occur in adults. Cutaneous findings may include erythematous to brown papules and plaques on intertriginous skin. Scale, weeping, crusts, ulcerations, and petechiae may occur in involved areas. Langerhans cell histiocytosis can also affect bone, lymph nodes, lungs, and other internal organs. A skin biopsy can confirm the diagnosis. (See "Clinical manifestations, pathologic features, and diagnosis of Langerhans cell histiocytosis", section on 'Clinical manifestations'.)

The differential diagnosis of intertrigo in the diaper area of infants is reviewed separately. (See "Diaper dermatitis", section on 'Differential diagnosis'.)

TREATMENT — Treatment of intertrigo is advised to improve symptoms and minimize risk for complications related to secondary infection. Although intertrigo is common, data on treatment are limited. The few randomized trials performed have methodologic flaws and considerable risk of bias [9]. A systematic review found insufficient evidence to confirm efficacy of any particular approach to treatment [9].

Practices aimed at minimizing moisture and friction in the involved area and reducing susceptibility to intertrigo are the mainstays of treatment. Typical beneficial practices include:

●Daily cleansing of intertriginous skin with a mild cleanser followed by drying of affected area with a hair dryer on a cool setting

●Aeration of affected area when feasible

●Daily application of drying powders, such as powders composed of microporous cellulose

●Use of absorbent material or clothing, such as cotton or merino wool, to separate skin in folds

●Application of barrier creams in areas that may come in contact with urine or feces

●Treatment of hyperhidrosis in the affected area

●Weight loss in persons who are overweight or obese

●Appropriate treatment of coexisting diabetes mellitus

Patients with incontinence-associated intertrigo often improve with the use of barrier creams to protect against the contact irritancy of urine and stool:

●Zinc oxide, petrolatum, or dimethicone topicals can be applied after cleaning the intertriginous area with mild soap and water and drying with a hair dryer on a cold setting.

●Super absorbent diapers can wick moisture away from the skin.

In addition to these measures, we routinely prescribe a topical azole antifungal cream (eg, ketoconazole, clotrimazole, miconazole, econazole) given the common presence of candidal infection and the additional antibacterial and anti-inflammatory effects of these drugs [10,11]. Benzylamines, such as butenafine 1% cream, and allylamines, such as naftifine 2% cream and terbinafine 1% cream, also have anti-inflammatory properties and are additional treatment options [12]. Once- or twice-daily application of the antifungal drug for two to four weeks is usually sufficient.  

Although nystatin is an option for treating candidal involvement in intertrigo, we favor other antifungal agents because of their anti-inflammatory and antibacterial effects. In addition, azole, benzylamine, and allylamine antifungal drugs are also effective for tinea cruris, a common condition that may be mistaken for intertrigo. (See 'Differential diagnosis' above.)

We usually reserve topical corticosteroid therapy for patients with marked pruritus given that the measures above are usually effective and the risk of skin atrophy associated with long-term topical corticosteroid use in intertriginous areas. We typically prescribe a low-potency (ie, group 7 (table 1)) topical corticosteroid, such as hydrocortisone 2.5%, applied twice daily for one week, once daily for one week, and every other day for one week. Pramoxine 1% is an alternative noncorticosteroid topical agent that may reduce pruritus. Use of combination antifungal/corticosteroid creams, such as betamethasone-clotrimazole and nystatin-triamcinolone, should be avoided because the corticosteroid is excessively potent, increasing the likelihood of local adverse effects. (See "Topical corticosteroids: Use and adverse effects", section on 'Adverse effects'.)

This combination of skin care measures and topical therapy usually leads to marked improvement in both signs and symptoms of intertrigo within a few weeks. The same regimen can be repeated for recurrences.

Alternative, less commonly used treatments include topical tacrolimus, iodochlorhydroxyquin (with or without hydrocortisone), and Castellani's paint. In one series, 10 adults with intertrigo (without associated infection) applied tacrolimus 0.1% ointment twice daily for six weeks. It is unclear whether local skin care measures were also incorporated. After one week, seven patients were clear or at least 75 percent clear; after six weeks, eight patients were clear. Burning at the site of application was the most common adverse effect. One patient withdrew from the study after two days due to burning and discomfort associated with drug application. A disadvantage of topical tacrolimus is higher cost compared with topical antifungal or corticosteroid therapy [13].

Iodochlorhydroxyquin ointment has both antifungal and antibacterial actions and is available in a combination with hydrocortisone 1% cream [14]. Castellani's paint is a topical antifungal agent; its use is limited by purple staining of skin and clothing.

Oral antifungal therapy can be effective for candidal intertrigo and is typically reserved for disease that fails to respond to topical therapy. Fluconazole is commonly used. A wide variety of dose regimens for fluconazole have been reported in the literature [15-19]. In a trial in which patients with cutaneous dermatophyte or candidal infections were randomly assigned to fluconazole 150 mg per week or 50 mg per day for up to four weeks, 10 of 11 and 12 of 13 patients treated for candidal infections with weekly or daily dosing, respectively, achieved clinical or mycologic cure by the end of treatment [16]. Our preferred regimen for fluconazole therapy for adults is 150 mg once weekly for four weeks. Oral ketoconazole should not be used for the treatment of intertrigo because of risk for hepatotoxicity and adrenal insufficiency.

Although typically not the sole indication for this intervention, surgical reduction of skin folds may lead to improvement in intertrigo. Reduction mammoplasty has been associated with reduced intertrigo in women with macromastia in uncontrolled studies [9].

PREVENTION OF RECURRENCE — Data on the efficacy of preventive interventions for intertrigo are lacking. In general, measures to minimize moisture within skin folds should be continued after successful treatment to minimize risk for recurrence. (See 'Treatment' above.)

We typically instruct patients to cleanse intertriginous areas daily with mild soap followed by drying with a hair dryer on a cool setting. Subsequently, a drying powder can be applied. In our experience, some patients with frequent recurrences may benefit from indefinite, once-weekly application of a topical azole antifungal medication.

SUMMARY AND RECOMMENDATIONS

●Etiology and pathogenesis – Intertrigo is a common cutaneous disorder characterized by inflammation of intertriginous skin. Moisture and friction within skin folds are important contributors to the development of this condition. (See 'Introduction' above.)

Fungal or bacterial infection or colonization of skin folds may initiate or exacerbate intertrigo. Allergic and irritant contact dermatitis are additional exacerbating factors. (See 'Pathogenesis' above.)

●Epidemiology and risk factors – Intertrigo may occur at any age but most often occurs in debilitated older adults and infants. Obesity, incontinence, poor hygiene, hyperhidrosis, and immune deficiencies are additional risk factors. (See 'Epidemiology and risk factors' above.)

●Clinical presentation – The classic clinical findings of intertrigo are moist, red or red-brown patches within skin folds (picture 1A-D). The groin is the most common site of involvement. Examples of other sites are the axilla, inframammary skin, umbilicus, neck folds in infants, under the panniculus, and finger and toe web spaces (erosio interdigitalis blastomycetica). Burning, tenderness, pruritus, and malodor may accompany the physical manifestations. (See 'Clinical presentation' above.)

Candidal skin infection commonly coexists with intertrigo. Satellite papules and pustules suggest candidal infection. (See 'Pathogenesis' above and 'Clinical presentation' above.)

●Diagnosis – Intertrigo usually can be diagnosed based upon recognition of the classic clinical findings. When the diagnosis is uncertain, a Wood's lamp examination, potassium hydroxide preparation, or skin biopsy can aid with differentiating intertrigo from other conditions. A bacterial culture should be obtained if there are signs of secondary bacterial infection. (See 'Diagnosis' above and 'Differential diagnosis' above.)

●Treatment – High-quality data on the efficacy of treatments for intertrigo are lacking. Implementation of measures to minimize moisture and friction in skin folds and reduce susceptibility to intertrigo is the mainstay of treatment.

In addition, we suggest application of a topical antifungal drug with anticandidal activity (Grade 2C). We typically use an azole because of the antifungal, anti-inflammatory, and antibacterial effects of azole antifungal drugs. A low-potency topical corticosteroid may be helpful for patients with significant pruritus. (See 'Treatment' above.)

●Prevention of recurrence – Intertrigo may recur after treatment. Measures to minimize moisture within skin folds should be continued after treatment to minimize risk for recurrence. (See 'Prevention of recurrence' above.)