Seborrheic Dermatitis: An Overview ROBERT A. SCHWARTZ, M.D., M.P.H., CHRISTOPHER A. JANUSZ, M.D., and CAMILA K. JANNIGER, M.D. University of Medicine and Dentistry at New Jersey-New Jersey Medical School, Newark, New Jersey Seborrheic dermatitis affects the scalp, central face, and anterior chest. In adolescents and adults, it often presents as scalp scaling (dandruff). Seborrheic dermatitis also may cause mild to marked erythema of the nasolabial fold, often with scaling. Stress can cause flare-ups. The scales are greasy, not dry, as commonly thought. An uncommon generalized form in infants may be linked to immunodeficiencies. Topical therapy primarily consists of antifungal agents and low-potency steroids. New topical calcineurin inhibitors (immunomodulators) sometimes are administered. (Am Fam Physician 2006;74:125-30. Copyright © 2006 American Academy of Family Physicians.) eborrheic dermatitis can affect patients levels, fungal infections, nutritional deficits, from infancy to old age.1-3 The con- neurogenic factors) are associated with the dition most commonly occurs in condition. The possible hormonal link may infants within the first three months explain why the condition appears in infancy, S of life and in adults at 30 to 60 years of age. In disappears spontaneously, then reappears adolescents and adults, it usually presents as more prominently after puberty. A more scalp scaling (dandruff) or as mild to marked causal link seems to exist between seborrheic erythema of the nasolabial fold during times dermatitis and the proliferation of Malassezia of stress or sleep deprivation. The latter type species (e.g., Malassezia furfur, Malassezia tends to affect men more often than women ovalis) found in normal dimorphic human and often is precipitated by emotional stress. flora.6-8 Yeasts of this genus predominate and An uncommon generalized form in infants are found in seborrheic regions of the body may be linked to immunodeficiencies. that are rich in sebaceous lipids (e.g., head, Seborrheic dermatitis and pityriasis capitis trunk, upper back). A causal relationship is (cradle cap) are common in early childhood. implied because of the ability to isolate Mal- According to one survey of 1,116 children,4 assezia in patients with seborrheic dermatitis the overall age- and sex-adjusted prevalence and by its therapeutic response to antifungal of seborrheic dermatitis was 10 percent in agents.9 A similar link has been suggested in boys and 9.5 percent in girls. The highest studies of patients with seborrheic dermatitis prevalence occurred in the first three months that is associated with acquired immunodefi- of life, decreasing rapidly by one year of age, ciency syndrome (AIDS).10,11 Seborrheic der- and slowly decreasing over the next four matitis also may be associated with nutritional years.4 Most patients (72 percent) had mini- deficiencies, but there is no firm linkage. mal to mild seborrheic dermatitis. Pityriasis An altered essential fatty acid pattern may capitis occurred in 42 percent of the children be important in the pathogenesis of infan- examined (86 percent had a minimal to mild tile seborrheic dermatitis. Serum essential case).4 Prevalence estimates for older persons fatty acid patterns from 30 children with the are consistently higher than estimates for the condition suggested a transient impaired general population.5 function of the delta-6 desaturase enzyme.12 A neurogenic theory for the development Etiology of seborrheic dermatitis may account for its Despite the high prevalence of seborrheic association with parkinsonism and other dermatitis, little is known about its etiol- neurologic disorders, including postcerebro- ogy. However, several factors (e.g., hormone vascular accidents, epilepsy, central nervous Downloaded from the American Family Physician Web site at www.aafp.org/afp. Copyright © 2006 American Academy of Family Physicians. For the private, noncommercial use of one individual user of the Web site. All other rights reserved. Contact [email protected] for copyright questions and/or permission requests. SORT: KEY RECOMMENDATIONS FOR PRACTICE Evidence Clinical recommendation rating References Infants with generalized seborrheic dermatitis, diarrhea, and C 14 failure to thrive should be evaluated for immunodeficiencies. The first-line therapy for seborrheic dermatitis of the scalp should C 2, 20, 34 be topical steroids. Topical calcineurin inhibitors (e.g., tacrolimus ointment [Protopic], B 26-28 pimecrolimus cream [Elidel]) are recommended for seborrheic dermatitis of the face and ears. Once-daily ketoconazole (Nizoral) combined with two weeks of B 22 once-daily desonide (Desowen) is recommended for seborrheic dermatitis of the face. A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evi- dence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, see page 17 or http://www.aafp.org/afpsort.xml. system trauma, facial nerve palsy, and syrin- Classification gomyelia induced by neuroleptic drugs with Adolescent and adult seborrheic dermatitis extrapyramidal effects.7 It may be confined usually starts as mild greasy scaling of the to the syringomyelia-affected area or to the scalp with erythema and scaling of the naso- paralyzed side in a patient with hemiplegia. labial folds (Figure 1) or the postauricular However, no neurotransmitters have been skin. The scaling often is concurrent with identified in this context. an oily complexion and appears in areas of increased sebaceous gland activity (e.g., auricles, beard area, eyebrows, trunk [flexure and inframammary areas; Figure 2]). Some- times the central face is involved (Figure 3). Blepharitis, with meibomian gland occlusion and abscess formation, otitis externa, and coexistent acne vulgaris or pityriasis versi- color, may be evident. Two types of seborrheic dermatitis may appear on the chest—a common petaloid type and a rarer pityriasiform type.2 The former starts as small, reddish-brown follic- ular and perifollicular papules with greasy Figure 1. Nasolabial fold scaling and ery- scales. These papules become patches that thema from seborrheic dermatitis. resemble the shape of flower petals or a medallion (medallion seborrheic dermati- tis). The pityriasiform type often has gen- eralized macules and patches that resemble extensive pityriasis rosea. These patches rarely produce an eruption so generalized that it causes erythroderma. In infants, seborrheic dermatitis may pres- ent as thick, greasy scales on the vertex of the scalp (cradle cap).2,3 The condition is not pruritic in infants, as it is in older children and adults. Typically, acute dermatitis (char- acterized by oozing and weeping) is absent. The scales may vary in color, appearing Figure 2. Severe persistent seborrheic dermatitis of the inframam- white, off-white, or yellow. Infants with large, mary folds. dry scales often have psoriasiform seborrheic 126 American Family Physician www.aafp.org/afp Volume 74, Number 1 ◆ July 1, 2006 Seborrheic Dermatitis TABLE 1 Differential Diagnosis of Seborrheic Dermatitis Atopic dermatitis Candidiasis Dermatophytosis Langerhans cell histiocytosis Psoriasis Rosacea Systemic lupus erythematosus Tinea infection children and adults (Figure 4). Highly active antiretroviral therapy may reduce incidence in patients with AIDS. Psoriasis vulgaris may be difficult to distin- guish from seborrheic dermatitis. Psoriasis vulgaris of the scalp presents as sharply demarcated scalp plaques. Other signs of psoriasis, such as nail pitting or distal ony- 16,17 Figure 3. Central facial erythema from sebor- cholysis, also may facilitate distinction. rheic dermatitis. Seborrheic dermatitis also may resemble atopic dermatitis, tinea capitis, and, rarely, dermatitis. This presentation often is the only cutaneous lymphoma or Langerhans cell sign of seborrheic dermatitis in infants and histiocytosis. Atopic dermatitis in adults usually occurs in the third or fourth week characteristically appears in antecubital and after birth. However, the scalp, central face, popliteal fossae. Tinea capitis, tinea faciei, forehead, and ears may have fine, widespread scaling. The dermatitis may become gener- alized. The flexural folds may be involved, often with a cheesy exudate that manifests as a diaper dermatitis that also may become gen- eralized. Generalized seborrheic dermatitis is uncommon in otherwise healthy children and usually is associated with immunode- ficiencies. Immunocompromised children with generalized seborrheic dermatitis often have concomitant diarrhea and failure to thrive5-8 (Leiner’s disease); therefore, infants with these symptoms should be evaluated for immunodeficiencies.13-15 Differential Diagnosis A number of disorders are similar to seb- orrheic dermatitis (Table 1). One study11 showed that 47 percent of patients with AIDS had recalcitrant eruptions similar to sebor- Figure 4. Generalized seborrheic dermatitis-like eruption associated rheic dermatitis that may be generalized in with acquired immunodeficiency syndrome. July 1, 2006 ◆ Volume 74, Number 1 www.aafp.org/afp American Family Physician 127 Seborrheic Dermatitis and tinea corporis may have hyphae on are a nonspecific finding. Rarely, infants potassium hydroxide cytologic examination; are affected by histologic-specific scaling, candidiasis produces pseudohyphae. Sebor- seborrheic dermatitis-like eruptions on the rheic dermatitis of the groin may resemble