Dermatology · PANCE / PANRE

Seborrheic Dermatitis

Written & clinically reviewed by Ryan Busch, PA-C · Updated October 2026 · Report an error

Chronic relapsing dermatitis of sebum-rich areas associated with Malassezia overgrowth; manifests as cradle cap (infants) and dandruff (adults).

Also known as: seborrheic dermatitis, seborrhea, dandruff, cradle cap, seb derm

Overview

A common chronic inflammatory dermatosis affecting sebum-rich areas (scalp, eyebrows, nasolabial folds, ears, chest, intertriginous folds) characterized by greasy yellow scale and erythema.

Epidemiology

Bimodal age distribution: infants (cradle cap) 0-3 months, resolves by 1 year; adults peak 30-60 years. Male predominance in adults. Prevalence about 1-5% in the general adult population; much higher in HIV and other immunocompromised states (reported in 34-83%), Parkinson disease, and other neurologic conditions.

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Question 1DermatologyEasy
A 4-month-old infant is brought to the clinic for a rash. Examination shows greasy yellow scales on the scalp and erythematous plaques in the diaper area. Which of the following is the most likely diagnosis?
  • AAtopic dermatitis
  • BDiaper dermatitis
  • CInfantile psoriasis
  • DTinea capitis
  • ESeborrheic dermatitis
Reveal answer & full explanation
Correct answer: E — Seborrheic dermatitis
  • AAtopic dermatitis
  • BDiaper dermatitis
  • CInfantile psoriasis
  • DTinea capitis
  • ESeborrheic dermatitis✓

Why Seborrheic dermatitis is correct

  • Seborrheic dermatitis is caused by overgrowth of Malassezia (Pityrosporum) yeast in sebum-rich areas
  • In infants (cradle cap): greasy yellow scales on the scalp, eyebrows, ears, nasolabial folds, and intertriginous areas including the diaper area — exactly matching this presentation
  • In adults: scalp dandruff, eyebrows, ears, nasolabial folds, chest, axillae
  • Worsened by HIV/AIDS, Parkinson disease, and immunosuppression
  • Treatment in infants: usually self-limited; emollients and gentle removal; antifungal shampoo (ketoconazole) if severe
  • Treatment in adults: ketoconazole shampoo, low-potency topical corticosteroid (short course), pyrithione zinc, selenium sulfide

Why the others are wrong

  • Tinea capitis — scaly scalp with alopecia; KOH preparation positive for hyphae; does not typically involve the diaper area
  • Atopic dermatitis — intensely pruritic with dry, fine scale rather than greasy yellow scale; in infants it favors the cheeks, scalp, and extensor surfaces and typically spares the diaper area; associated with personal/family history of atopy
  • Diaper dermatitis — confined to the diaper area; often complicated by Candida superinfection; does not involve the scalp with greasy yellow scales
  • Infantile psoriasis — the classic look-alike, because psoriasis in infants also favors the scalp and the diaper area, but on the scalp it forms sharply demarcated plaques with thick silvery-white scale rather than greasy yellow scale, and it is uncommon at 4 months; greasy yellow scalp scale with diaper-area plaques is the cradle-cap pattern of seborrheic dermatitis
Question 2DermatologyMedium
A 34-year-old man presents with several months of an itchy, flaky rash. On exam he has erythematous patches with greasy yellow scale involving the eyebrows, glabella, nasolabial folds, and postauricular sulci, along with fine flaking of the scalp. The findings are symmetric and have waxed and waned with the seasons. A diagnosis of seborrheic dermatitis is made. Which of the following best explains the findings?
  • AType IV hypersensitivity to a contact allergen at the site of exposure
  • BKeratinocyte hyperproliferation driven by the IL-17 and IL-23 cytokine axis
  • CMalassezia yeast lipase liberates irritating free fatty acids from sebum
  • DFilaggrin loss-of-function impairing the epidermal barrier layer
  • EAndrogen-driven sebaceous hyperplasia with comedonal follicular plugging
Reveal answer & full explanation
Correct answer: C — Malassezia yeast lipase liberates irritating free fatty acids from sebum
  • AType IV hypersensitivity to a contact allergen at the site of exposure
  • BKeratinocyte hyperproliferation driven by the IL-17 and IL-23 cytokine axis
  • CMalassezia yeast lipase liberates irritating free fatty acids from sebum✓
  • DFilaggrin loss-of-function impairing the epidermal barrier layer
  • EAndrogen-driven sebaceous hyperplasia with comedonal follicular plugging

Why Malassezia yeast lipase liberates irritating free fatty acids from sebum is correct

  • Seborrheic dermatitis is a multifactorial inflammatory dermatosis of sebum-rich skin (scalp, eyebrows, nasolabial folds, ears, chest).
  • Malassezia, a lipophilic commensal yeast, uses lipases to metabolize sebum triglycerides into free fatty acids (e.g., oleic acid) that irritate the skin and trigger an inflammatory response to fungal antigens in susceptible hosts.
  • It is NOT a simple infection: increased sebum production, altered lipid composition, and abnormal innate immunity all contribute, which is why antifungal (ketoconazole) shampoos plus low-potency topical steroids are first-line.

Why the others are wrong

  • Type IV hypersensitivity to a contact allergen at the site of exposure - this is the mechanism of allergic contact dermatitis, which produces a rash limited to the area of allergen contact, not a symmetric greasy eruption in a sebaceous distribution.
  • Keratinocyte hyperproliferation driven by the IL-17 and IL-23 cytokine axis - this is the pathophysiology of psoriasis, which produces sharply demarcated thick silvery plaques on extensor surfaces; sebopsoriasis can overlap, but the greasy yellow scale in a sebaceous distribution here points to Malassezia-driven seborrheic dermatitis.
  • Filaggrin loss-of-function impairing the epidermal barrier layer - filaggrin null mutations are the strongest known genetic risk factor for atopic dermatitis (and cause ichthyosis vulgaris); atopic dermatitis produces intensely pruritic, poorly demarcated eczematous plaques with xerosis in flexural sites in a patient with an atopic history, not symmetric greasy yellow scale confined to sebum-rich areas.
  • Androgen-driven sebaceous hyperplasia with comedonal follicular plugging - the name seborrheic and the greasy scale in sebum-rich sites suggest a primary sebaceous gland disorder, but hyperplasia with comedonal plugging describes acne vulgaris; seborrheic dermatitis has no comedones, and sebum here is the substrate that Malassezia metabolizes rather than the gland pathology itself.

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Risk factors

  • HIV/AIDS — severe and refractory disease
  • Parkinson disease and other parkinsonian syndromes
  • Neurologic conditions: stroke, spinal cord injury, depression, tardive dyskinesia
  • Immunosuppression (transplant, chemotherapy)
  • Cold dry weather, emotional stress
  • Medications: lithium, interferon, EGFR inhibitors, neuroleptics

Pathophysiology

Multifactorial. Malassezia (M. furfur, M. globosa, M. restricta) — a lipophilic commensal yeast — metabolizes sebum lipids into irritating free fatty acids that trigger inflammation in susceptible hosts. Increased sebum production, abnormal lipid composition, and altered innate immunity contribute. Not a simple infection — represents an inflammatory response to fungal antigens.

Clinical presentation

Symptoms

  • Mild pruritus or burning, especially scalp
  • Visible scaling and erythema, often worse in winter
  • Cosmetic concern, embarrassment

Signs / physical exam

  • Scalp: fine flaky to thick greasy yellow scale; diffuse or patchy; erythema
  • Face: erythematous patches with greasy scale in eyebrows, glabella, nasolabial folds, mustache/beard, postauricular sulcus, external auditory canal
  • Chest: petaloid erythematous patches in midline sternal region
  • Intertriginous: erythematous macerated plaques in axillae, inguinal folds, intergluteal cleft, umbilicus
  • Infant cradle cap: thick adherent greasy yellow scale on vertex; non-pruritic; may extend to face, ears, neck, diaper area

Classic findings

Greasy yellow scale on erythematous base in sebaceous distribution; nasolabial fold involvement; postauricular fissures.

Differential diagnosis

  • Psoriasis (sebopsoriasis overlap) — Sharply demarcated thick silvery scale, extensor surfaces, nails, Auspitz sign
  • Atopic dermatitis — Pruritus prominent, flexural distribution, personal/family atopy
  • Tinea capitis (children) — Patchy alopecia with scale and broken hairs; KOH/fungal culture positive; black-dot ringworm
  • Rosacea — Centrofacial erythema with papules/pustules and telangiectasias; can coexist with seb derm
  • Lupus (subacute cutaneous) — Photo-distributed annular or psoriasiform plaques; ANA/SSA positive
  • Pityriasis versicolor — Hypo/hyperpigmented finely scaling macules on trunk; spaghetti-and-meatballs on KOH
  • Langerhans cell histiocytosis (infants) — Recalcitrant seborrheic-like scalp/diaper eruption with petechiae, hepatosplenomegaly, lytic bone lesions

Diagnostic workup

Diagnostic criteria

Clinical: scaling and erythema in characteristic sebaceous distribution with chronic relapsing course.

Labs

  • Clinical diagnosis
  • Consider HIV testing if sudden, severe, or refractory disease, especially in young adults
  • KOH preparation if tinea or pityriasis versicolor cannot be excluded
  • Skin biopsy rarely needed; shows spongiosis with neutrophils at follicular ostia, parakeratosis

Imaging

  • Not indicated

Diagnostic algorithm

SiteTypical LesionPreferred Therapy
Scalp (adult)Greasy yellow scale, erythemaKetoconazole/selenium sulfide/zinc pyrithione shampoo 2-3x/wk
Face / nasolabial foldsErythematous patches with greasy scaleKetoconazole 2% cream + low-potency steroid or TCI
IntertriginousMacerated erythematous plaquesKetoconazole/ciclopirox cream + short low-potency steroid
Infant scalp (cradle cap)Thick adherent yellow scaleMineral oil/emollient + gentle brushing; ketoconazole 2% if persistent
Severe / HIV-associatedWidespread, refractoryCombination topical + oral itraconazole; treat HIV
Site-based therapy for seborrheic dermatitis.

Treatment

First-line

  • Adult scalp (dandruff/mild-moderate): ketoconazole 2% shampoo, selenium sulfide 2.5% shampoo, zinc pyrithione 1-2% shampoo, ciclopirox 1% shampoo, or coal tar shampoo — 2-3x/week, lather and leave on 5 min before rinsing
  • Adult scalp (severe/plaque): high-potency topical corticosteroid solution/foam — clobetasol 0.05%, fluocinonide — short courses (≤2 weeks) over antifungal shampoo base
  • Face/intertriginous: topical antifungal — ketoconazole 2% cream, ciclopirox 0.77% cream BID + low-potency topical corticosteroid (hydrocortisone 1%) or topical calcineurin inhibitor (tacrolimus, pimecrolimus) for short pulse
  • Topical roflumilast 0.3% foam — PDE4 inhibitor, FDA-approved for scalp/body seb derm ages ≥9
  • Infant cradle cap: emollient (mineral oil, petrolatum) overnight, gentle brushing, baby shampoo; mild ketoconazole 2% cream short course if persistent — self-limited

HIV-associated severe / refractory

  • Combine topical antifungal + topical corticosteroid + intensive scalp shampoo regimen
  • Address underlying HIV with antiretroviral therapy
  • Oral itraconazole 200 mg/day × 1-2 weeks for severe widespread disease

Second-line / adjunct

  • Oral itraconazole or fluconazole pulse therapy for refractory adult disease
  • Topical lithium succinate/gluconate (off-label, available in Europe)
  • Photodynamic therapy or low-dose narrowband UVB for stubborn facial disease
  • Avoid greasy ointments which can worsen Malassezia overgrowth

Complications

  • Cosmetic distress, social embarrassment
  • Secondary bacterial infection from scratching/maceration
  • Otitis externa from auditory canal involvement
  • Steroid-induced atrophy, telangiectasia, perioral dermatitis from chronic high-potency use
  • Erythroderma (rare, in HIV/immunocompromised)

PANCE pearls

  • Sudden severe seborrheic dermatitis in a young adult should prompt HIV testing.
  • Seborrheic dermatitis can involve the eyelid margins as seborrheic blepharitis (greasy scale at the lash line).
  • Cradle cap is self-limited — reassure parents and treat conservatively with emollients first.
  • Sebopsoriasis describes overlapping features and may respond better to vitamin D analogues (calcipotriene) in addition to antifungals.
  • Beard area (sycosis-like) seb derm responds well to ketoconazole cream — patients often misdiagnosed as folliculitis.

References

  • Cochrane 2014 — Topical Antifungals for Seborrhoeic Dermatitis (Okokon et al., Cochrane Database Syst Rev 2015)
  • AAFP — Diagnosis and Treatment of Seborrheic Dermatitis (Clark et al., Am Fam Physician 2015)

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Commonly confused with

vs Psoriasisvs Atopic Dermatitis

Related Dermatology diagnoses

Acne VulgarisRosaceaAtopic Dermatitis (Eczema)Allergic and Irritant Contact DermatitisPsoriasisLichen PlanusPityriasis RoseaTinea Infections (corporis, capitis, pedis, cruris, versicolor)Cutaneous CandidiasisScabiesPediculosisImpetigoHerpes Zoster (Shingles)Verrucae (Warts, HPV)

Differentials & related conditions

Systemic Lupus Erythematosus (SLE)

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