Cradle cap and seborrheic dermatitis in infants

INTRODUCTION — Seborrheic dermatitis is a self-limiting eruption consisting of erythematous plaques with greasy-looking, yellowish scales or hypopigmented, scaly patches distributed on areas rich in sebaceous glands, such as the scalp (picture 1A-C), the external ear, the center of the face, and the intertriginous areas.

This topic will discuss cradle cap and seborrheic dermatitis in infants. Seborrheic dermatitis in adolescents and adults is discussed separately. (See "Seborrheic dermatitis in adolescents and adults".)

EPIDEMIOLOGY — Seborrheic dermatitis occurs in infants between the ages of 3 weeks and 12 months. It has been reported in approximately 10 percent of infants younger than one month [1]. The prevalence peaks at the age of three months (approximately 70 percent) and decreases steadily in the following months, affecting approximately 7 percent of children aged one to two years [2].

PATHOGENESIS — The pathogenesis of infantile seborrheic dermatitis is not known. Transplacental transfer of maternal androgens stimulates the growth of the infant's sebaceous glands, which are necessary but not sufficient for the development of seborrheic dermatitis. The role of Malassezia, a lipid-dependent yeast, is not clear. Malassezia colonization has been reported in infants with seborrheic dermatitis, infants with other dermatologic conditions, and in normal infants [3-5].

CLINICAL MANIFESTATIONS — The most common manifestation of seborrheic dermatitis in newborns and infants is "cradle cap," an asymptomatic and noninflammatory accumulation of yellowish, greasy scales on the scalp (picture 1A-B). The vertex and the frontal area are commonly involved. Sometimes the eruption starts on the face, with erythematous, scaly, salmon-colored plaques (picture 2). In infants with skin of color, seborrheic dermatitis may present with hypopigmented, scaly patches (picture 1C). The forehead, the retroauricular areas, eyebrows and eyelids, cheeks, and nasolabial folds are commonly affected (picture 1D). Seborrheic dermatitis may also occur in the napkin (diaper) area (picture 3), on the trunk, with a predilection for the umbilical area, or in the intertriginous areas. It also may occur simultaneously at multiple sites (picture 4).

In the folds around the neck, in the axillae, and the crural region, the lesions have a moist, glistening, nonscaly aspect and tend to be confluent. In more widespread forms, large areas of the trunk may become involved with sharply marginated plaques of erythema and scaling that cover the lower abdomen, pubic and groin area, as well as the buttocks. Rarely, seborrheic dermatitis may present as an erythrodermic eruption in infants [6,7].

The infant is generally well; feeding and sleep are not disturbed. The pruritus is mild in most cases. The clinical manifestations fluctuate, but most cases eventually resolve spontaneously within weeks to a few months. Cases persisting beyond the age of 12 months are rare and require the diagnosis to be reconsidered. (See 'Differential diagnosis' below.)

DIFFERENTIAL DIAGNOSIS — Several inflammatory skin disorders may present in the infant with features resembling seborrheic dermatitis. In the evaluation of an infant with atypical seborrheic dermatitis that does not resolve with standard treatment, Langerhans cell histiocytosis should be considered in the differential diagnosis:

●Atopic dermatitis – Atopic dermatitis is the other major dermatitis of infancy. It is characterized by severe pruritus that interferes with feeding and sleep. The erythematous, scaly, and crusted lesions of atopic dermatitis are generally poorly demarcated, and commonly involve the cheeks, scalp, and extensor surfaces of the limbs (picture 5A-C). The diaper area is usually spared (picture 6). A positive family history of eczema, asthma, and allergic rhinitis is often present. (See "Atopic dermatitis (eczema): Pathogenesis, clinical manifestations, and diagnosis", section on 'Clinical manifestations'.)

●Diaper dermatitis – Irritant diaper dermatitis is caused by the moist environment and friction of the diaper. In contrast to seborrheic dermatitis, it usually spares the skin folds. However, diaper dermatitis with superimposed Candida infection has a beefy red, glistening appearance, sometimes with superficial erosions, and involves the skin folds. Transient pustules may be seen at the advancing borders, and satellite lesions are common (picture 7). Infrequently, diaper dermatitis may spread beyond the diaper area and become disseminated, with a pattern resembling seborrheic dermatitis. (See "Diaper dermatitis".)

●Psoriasis – Psoriasis is uncommon in infants, but can mimic seborrheic dermatitis, especially when it involves the flexures or the diaper area. The psoriatic plaques are sharply defined, shiny and bright red in color, with the typical large, silvery scales of psoriasis usually seen in nonintertriginous areas (picture 8). (See "Psoriasis: Epidemiology, clinical manifestations, and diagnosis", section on 'Clinical manifestations'.)

●Langerhans cell histiocytosis – Langerhans cell histiocytosis may present in infancy as a refractory seborrheic dermatitis or as diaper dermatitis with ulceration and erosion. Sometimes, papules and brownish-red or purpuric nodules can be seen on the scalp, retroauricular areas, axillae, and inguinocrural folds (picture 9A-B). A skin biopsy will confirm the diagnosis. (See "Clinical manifestations, pathologic features, and diagnosis of Langerhans cell histiocytosis".)

●Tinea capitis – In infants, tinea capitis may present as a scaly scalp dermatitis with moderate or minimal inflammation (picture 10). Hair loss generally is present but is not always easy to detect. KOH examination of the hair shaft and fungal cultures will confirm the diagnosis. Tinea is rare in infants. (See "Tinea capitis".)

MANAGEMENT

Cradle cap — In infants, seborrheic dermatitis has a self-limited course and resolves spontaneously in weeks to several months. Therefore, we suggest that initial treatment should be conservative, including education and reassurance of parents/caregivers and simple skin care measures.

Conservative measures for scalp seborrheic dermatitis may include:

●Application of an emollient (white petrolatum, vegetable oil, mineral oil, baby oil) to the scalp (overnight, if necessary) to loosen the scales, followed by removal of scales with a soft brush (eg, a soft toothbrush) or fine-tooth comb

●Frequent shampooing with mild, nonmedicated baby shampoo followed by removal of scales with a soft brush (eg, a soft toothbrush) or fine-tooth comb

In more extensive or persistent cases, we suggest a short course of low-potency topical corticosteroids (group 7 (table 1)) applied once per day for one week, ketoconazole 2% shampoo twice per week for two weeks, or ketoconazole 2% cream once or twice daily for two weeks or until sufficient improvement is noted. Corticosteroids are preferred if there is a predominant inflammatory component; ketoconazole 2% cream or shampoo is an alternative in diffuse cases or if the use of topical corticosteroids is a concern for the parents/caregivers [8].

Ketoconazole shampoo may cause eye irritation. The use of lower-potency topical corticosteroids in children is generally safe when used for short durations. (See "Topical corticosteroids: Use and adverse effects".)

There are no randomized trials of antifungal agents or topical corticosteroids for the treatment of cradle cap in infants. In a nonrandomized study of 48 children aged two weeks to two years, ketoconazole 2% cream was equivalent to 1% hydrocortisone cream in clearing the lesions in two weeks [9].

Due to the scarcity of data concerning the safety of topical ketoconazole in the pediatric population, the manufacturer of ketoconazole shampoo and cream recommends limiting its use to individuals older than 12 years of age, except under the advice of a clinician. In clinical practice, topical ketoconazole has been used in infants and children without adverse effects. Systemic absorption of topical ketoconazole in infants has been evaluated in two studies. In one, ketoconazole 2% shampoo used twice a week for four weeks in 13 infants (<12 months) produced no detectable serum ketoconazole levels and no abnormalities of liver function tests [10]. In the other, ketoconazole 2% cream was used once daily for 10 days to treat 19 children with seborrheic dermatitis of the scalp and diaper area. Peak plasma levels of ketoconazole detected one to three hours after topical treatment were 1 to 2 percent of those measured after systemic administration [11].

Other antiseborrheic shampoos (eg, selenium sulfide 2.5%, zinc pyrithione, salicylic acid) have been used in the treatment of infantile seborrheic dermatitis. However, there are no clinical trials evaluating their efficacy and safety in infants. Observational studies in adults suggest that shampoos and ointments containing salicylic acid may result in systemic toxicity because of transcutaneous absorption [12].

Nonscalp, nonintertriginous seborrheic dermatitis — We suggest that seborrheic dermatitis involving body areas other than the scalp in infants be treated with ketoconazole 2% cream (once a day for one to two weeks) or a low-potency topical corticosteroid (eg, hydrocortisone 1% cream once a day). The use of topical corticosteroids should be limited to the time needed to achieve the clearing of the lesions, but no longer than one week (see 'Recalcitrant dermatitis' below). Emollients can be used liberally.

There are no randomized trials evaluating the treatment of nonscalp seborrheic dermatitis in infants. A single randomized trial in adults suggested that ketoconazole 2% cream and mid-potency corticosteroids are equally effective. We generally use only low-potency topical corticosteroids for seborrheic dermatitis in infants given the natural history of spontaneous resolution and the potential for systemic absorption of topical corticosteroids. (See "Topical corticosteroids: Use and adverse effects", section on 'Use in children'.)

Neck folds and other intertriginous areas — We suggest that infants with seborrheic dermatitis of the intertriginous areas be treated with a topical azole (ketoconazole 2% cream or other azole preparation, once a day for one to two weeks). In addition, topical creams or ointments containing zinc oxide and/or petrolatum may be applied liberally. Although there are no randomized trials evaluating this therapy, seborrheic dermatitis involving the intertriginous areas is frequently superinfected with Candida albicans. The topical barrier helps to limit skin maceration.

Recalcitrant dermatitis — If the rash does not improve after one week of corticosteroid therapy or two weeks of antifungal therapy as described above, the diagnosis should be reconsidered. (See 'Differential diagnosis' above.)

If the diagnosis of infantile seborrheic dermatitis is confirmed, intermittent courses of treatment may be needed, since the disease may recur for weeks to months before disappearing.

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: Seborrheic dermatitis".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Seborrheic dermatitis (The Basics)")

●Beyond the Basics topics (see "Patient education: Seborrheic dermatitis (including dandruff and cradle cap) (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Epidemiology – Seborrheic dermatitis is a very common and self-limited condition occurring in infants between 3 weeks and 12 months of age, with a peak prevalence at the age of three months. (See 'Epidemiology' above.)

●Clinical manifestations – In infants, seborrheic dermatitis most frequently involves the scalp (cradle cap (picture 1A-B)) but may involve the face and neck (picture 1C-D), the trunk, diaper area (picture 3), or multiple sites at the same time (picture 4).

●Management:

•Cradle cap – The initial treatment of scalp seborrheic dermatitis includes education, reassurance, and conservative measures (emollients and frequent shampooing) to soften and remove the scales. If conservative measures fail, we suggest either topical low-potency corticosteroids (group 7 (table 1)) or ketoconazole 2% shampoo or cream (Grade 2C). A topical corticosteroid is applied once per day for one week. Ketoconazole 2% shampoo or cream is used twice per week for two weeks. (See 'Cradle cap' above.)

•Nonscalp, nonintertriginous areas – For seborrheic dermatitis of areas other than the scalp, we suggest ketoconazole 2% cream or a low-potency corticosteroid cream (table 1) (Grade 2C). Ketoconazole 2% cream should be applied once a day for one to two weeks. A topical corticosteroid is applied once a day for up to one week. (See 'Nonscalp, nonintertriginous seborrheic dermatitis' above.)

•Intertriginous areas – For seborrheic dermatitis of the intertriginous areas, we suggest ketoconazole 2% cream or other azole cream (Grade 2C). The azole cream is applied once a day for one to two weeks. In addition, topical creams or ointments containing zinc oxide and/or petrolatum may be applied liberally. (See 'Neck folds and other intertriginous areas' above.)

•Recalcitrant dermatitis – If the rash does not resolve or improve considerably after one week of corticosteroid therapy or two weeks of antifungal therapy as described above, the diagnosis should be reconsidered. (See 'Differential diagnosis' above.)

If the diagnosis of infantile seborrheic dermatitis is confirmed, intermittent courses of treatment may be needed, since the disease may recur for weeks to months before disappearing.