Seborrheic Dermatitis

Seborrheic dermatitis is a chronic, relapsing inflammatory skin condition driven by an individual's inflammatory response to Malassezia yeast — a fungus that lives normally on everyone's skin — rather than by a true infection or an external contact trigger.^[1][2] It affects the sebum-rich ("seborrheic") areas of the body: the scalp, the face (especially the eyebrows, glabella, nasolabial folds, and ears), the central chest, and body folds.^[2] Dandruff is simply the mild, non-inflammatory end of this same spectrum — fine scalp scaling without significant redness — while seborrheic dermatitis proper adds visible erythema and thicker, greasy, yellow-white scale.^[3][1] An important, distinct presentation of the same underlying process occurs in infants as cradle cap — see Special Populations.

Overall prevalence is reported at roughly 1-5% of the general population, and age follows a genuinely bimodal pattern: a peak in infancy (2-12 months, as cradle cap) and a second peak in adolescence and early adulthood, when sebaceous gland activity rises.^[1][4] The condition is more common, and tends to run more severe, in men, an observation consistently attributed to androgen-driven sebaceous gland activity.^[1][3][4] Two associations are clinically important enough to actively screen for. Seborrheic dermatitis is markedly more common in HIV-positive patients — roughly 30-83%, compared with 3-5% in the general population — and often serves as one of the earliest cutaneous markers of HIV infection, sometimes preceding the diagnosis itself.^[4] It is also significantly more prevalent in Parkinson's disease: a recent cross-sectional study found it in roughly two-thirds of patients with Parkinson's disease, compared with about 1 in 10 controls, with severity tracking Parkinson's motor-symptom severity.^[5] See Etiology and Risk Factors and Special Populations for the full detail on both. Flares are also reliably provoked by cold, dry weather and by emotional stress.^[1][4][3]

Pathophysiology — why this looks the way it does

The pathophysiology has three interacting pieces: overgrowth of Malassezia species (principally M. furfur, M. globosa, and M. restricta) on sebum-rich skin; the yeast's lipase activity, which breaks down sebum triglycerides into free fatty acids that directly irritate the epidermis and trigger inflammation; and an individual, genetically-influenced inflammatory and immune response to that irritation, which is what actually determines whether a given amount of yeast produces visible disease in a given patient.^[1][2] Skin-surface lipid quantity and composition also differ measurably between affected patients and unaffected controls, supporting a real sebum/hormonal contribution alongside the yeast itself.^[4] This is a genuinely different mechanism from irritant or allergic contact dermatitis, which are trigger-driven direct skin-barrier injuries or Type IV hypersensitivity reactions to an external substance the skin has directly touched. Seborrheic dermatitis is not a contact reaction, has no identifiable external trigger to avoid, and is not caused by, or a form of, either type of contact dermatitis — this is exactly why it is covered as its own chapter, separate from this platform's Contact Dermatitis chapter, rather than as a subtype within it.

Distribution — sebum-rich sites

Where it shows up, and how it looks

Scalp

The most common site, and the one where the disease spectrum is easiest to see end to end: fine, dry or greasy white flaking without significant redness (dandruff, the mild, non-inflammatory end of the spectrum) grades into frank seborrheic dermatitis — erythematous patches with thicker, greasy, yellow-white scale, sometimes with mild itching.^[3][1]

Seborrheic dermatitis of the scalp — erythematous, scaly patches at the more inflamed end of the dandruff-to-seborrheic-dermatitis spectrum. (Amras666, CC BY-SA 3.0, Wikimedia Commons)

Face

The eyebrows, glabella (between the brows), nasolabial folds, and the skin behind and within the ears are the classic facial sites, along with the eyelid margins (blepharitis).^[1][2] Erythema and greasy scale concentrated in these specific sites, rather than a diffuse facial rash, is a genuinely useful pattern-recognition clue.

Facial seborrheic dermatitis — erythema and scaling concentrated around the nasolabial folds, the classic facial distribution. (Roymishali, CC BY-SA 3.0, Wikimedia Commons)

Chest, body folds, and other sites

The central anterior chest, upper back, axillae, and groin can all be involved, following the same sebum-rich, fold-prone distribution as the scalp and face.^[2]

Darker skin tones

Seborrheic dermatitis in richly pigmented skin more often presents as petaloid seborrheic dermatitis — annular (ring-shaped), petal-like patches, sometimes with pronounced hypo- or hyperpigmentation that can persist well after the inflammation itself has cleared — rather than the straightforward erythema seen in lighter skin.^[3][2] Counsel proactively that this pigment change is an expected part of the disease course, not a sign of treatment failure or a different diagnosis (see Patient Education within Monitoring and Follow-Up).

• Male sex — androgen-driven sebaceous gland activity is the leading explanation for both the higher prevalence and the greater severity seen in men.^[1][3][4]
• Age: the bimodal peaks of infancy (2-12 months, presenting as cradle cap) and adolescence/early adulthood, both periods of relatively higher sebaceous gland activity.^[1]
• HIV infection/immunosuppression — prevalence rises to roughly 30-83% in HIV-positive patients, compared with 3-5% in the general population, and seborrheic dermatitis often appears early in the course of HIV disease, sometimes as one of its first cutaneous signs; in some settings its appearance has been used as a practical predictor of underlying HIV infection.^[4] See Diagnosis/Differential and Red Flags/Refer for when to consider HIV testing.
• Parkinson's disease — a recent cross-sectional study found seborrheic dermatitis in 66.6% of patients with akinetic-rigid Parkinson's disease and 69.7% of patients with tremor-predominant Parkinson's disease, compared with 10% of essential-tremor controls, with the akinetic-rigid group also showing significantly greater seborrheic dermatitis severity — plausibly reflecting shared cutaneous autonomic dysfunction.^[5]
• Other neurologic conditions, including a history of stroke, are also associated with increased prevalence.^[1]
• Cold, dry weather and season — symptoms characteristically worsen in winter and improve in summer.^[3][1]
• Emotional stress and fatigue are recognized triggers for flares.^[4][1]
• Family history of seborrheic dermatitis.
• Concurrent psoriasis or rosacea — an overlapping predisposition, and a source of diagnostic overlap (sebopsoriasis); see Diagnosis/Differential.

Complications

Left unaddressed, seborrheic dermatitis can be complicated by secondary bacterial or fungal infection of excoriated or fissured skin, by genuine treatment-induced harm (skin atrophy, telangiectasia, or a perioral-dermatitis-like eruption from prolonged, unsupervised topical corticosteroid use on the face), and — in richly pigmented skin — by postinflammatory hypo- or hyperpigmentation that can persist for weeks to months after the inflammation itself clears.^[3][2] A more indirect but clinically important complication is diagnostic delay: missing seborrheic dermatitis as an early cutaneous marker of HIV infection, or failing to recognize its association with Parkinson's disease, both represent missed opportunities to identify or address a more consequential underlying condition.^[4][5]

Diagnosis is clinical

Seborrheic dermatitis is diagnosed by the location and appearance of the lesions — no laboratory test is routinely needed.^[1] Ask specifically about symmetry, whether the distribution matches the classic sebum-rich sites, itch versus pain, and any known HIV status, neurologic diagnosis (particularly Parkinson's disease), or family history.

Differential diagnosis

Investigations

Most patients need no testing beyond a careful history and examination. Reserve skin biopsy for genuine diagnostic uncertainty, particularly to distinguish seborrheic dermatitis from psoriasis or sebopsoriasis — supportive biopsy findings include parakeratosis, plugged follicular ostia, and spongiosis.^[1] Perform KOH microscopy of scale when tinea is a realistic possibility, especially before adding or increasing topical corticosteroid potency, since an unrecognized fungal infection will predictably worsen under corticosteroid treatment. Consider HIV testing in an adult with new, severe, widespread, or treatment-refractory seborrheic dermatitis and no other clear explanation, particularly alongside other risk indicators — see Red Flags/Refer.^[4]

• Control visible scale, erythema, and itch to an acceptable, cosmetically satisfactory level — this is a chronic, relapsing condition, and complete, permanent clearance from a single course is not a realistic goal.
• Match treatment potency and formulation to the affected site, with particular care on the face, where the skin is thin and corticosteroid side effects appear more readily.
• Correctly distinguish seborrheic dermatitis from psoriasis, atopic dermatitis, contact dermatitis, and tinea, since each has a genuinely different core treatment strategy.
• Establish a sustainable long-term maintenance strategy — typically an antifungal shampoo or cream continued once or twice weekly — rather than relying on repeated corticosteroid courses alone.
• Use a gentle, reassurance-focused approach in infants with cradle cap, reserving active treatment for extensive or persistent cases.
• Recognize when seborrheic dermatitis severity or distribution should prompt consideration of an underlying HIV infection or a neurologic condition such as Parkinson's disease, and act on that recognition.
• Avoid the specific, well-documented pitfalls of prolonged high-potency topical corticosteroid use on thin, sebum-rich facial skin.

• Regular, gentle shampooing — 2-3 times weekly for straight or wavy hair, up to daily for a very oily scalp, and less often (roughly weekly) for coily/textured hair, adjusting to the patient's actual hair type and washing tolerance.^[3][1]
• Use a mild, fragrance-free cleanser on the face and body rather than harsh soap, which can itself irritate already-inflamed skin.
• Do not vigorously scrub or pick at scale — this worsens inflammation and irritation without speeding clearance.
• For infant cradle cap: soften scales first with a bland emollient (mineral oil or plain petroleum jelly) left on for several minutes to about an hour, then gently loosen and remove loose scale with a soft brush or washcloth before a mild baby shampoo — never use an adult dandruff or tar shampoo on an infant's scalp.^[1][6]
• Reassure caregivers that cradle cap is benign, is not caused by poor hygiene, is not contagious, and typically resolves on its own within the first year of life.^[3][6]
• Counsel that seborrheic dermatitis at any age is not caused by poor hygiene and is not contagious — a common and unhelpful misconception worth actively correcting.^[6]
• Manage cold-weather and stress-related flares proactively wherever a clear seasonal or stress pattern is identified, since both are recognized triggers.^[3][4]

Infants (cradle cap)

Cradle cap is infantile seborrheic dermatitis of the scalp, typically appearing between 2 and 12 months of age as thick, greasy, white-to-yellow scale, sometimes with mild underlying erythema, and occasionally extending to the eyebrows, ears, or diaper area.^[1][6] It is a benign, self-limited condition that resolves spontaneously, usually within the first several months to about a year of life, and needs no medication in the great majority of cases — gentle emollient softening plus brushing and a mild shampoo is both first-line and usually sufficient (see Non-Pharmacologic Management).^[3][6][1] Reserve topical ketoconazole or a brief low-potency corticosteroid course for extensive, thick, or persistent disease, and remember that no medicated dandruff shampoo is approved for children under 2 years — do not substitute an adult antifungal or tar shampoo.^[1]

Cradle cap in a 2-month-old infant — thick, yellow-brown, greasy scale on the scalp, the classic infantile seborrheic dermatitis presentation. (LepoRello, CC BY-SA 3.0, Wikimedia Commons)

Pregnancy

Breastfeeding

Topical antifungals and low-to-moderate potency topical corticosteroids are compatible with breastfeeding; wash the treated area before the next feed if applied near the breast or nipple. Topical calcineurin inhibitors are also generally considered compatible given minimal systemic absorption.

Older adults

Skin thins with age, increasing both topical corticosteroid absorption and the visible impact of atrophy and purpura — favour topical antifungals and topical calcineurin inhibitors as first-line, and use the lowest effective corticosteroid potency for the shortest effective course. Seborrheic dermatitis is also more prevalent in patients with neurologic disease more common in this age group, including Parkinson's disease and a history of stroke — a new or worsening presentation may be worth flagging to the treating physician rather than assumed to be purely dermatologic.^[1]

Darker skin tones

Petaloid (annular, ring-shaped) presentation is more common, and postinflammatory hypo- or hyperpigmentation is a genuinely expected part of the disease course that can persist for weeks to months after the inflammation itself has cleared — counsel on this explicitly so it is not mistaken for treatment failure or a different diagnosis.^[3][2]

HIV infection and other immunosuppression

Seborrheic dermatitis is markedly more prevalent (roughly 30-83%) and tends to be more severe, more widespread, and more difficult to treat in HIV-positive patients than in the general population, and it commonly appears early in the course of HIV disease — sometimes as one of the first clinical signs.^[4] A butterfly-distribution facial rash that does not respond to standard treatment can even be mistaken for discoid lupus erythematosus unless the underlying immunosuppression is recognized, and tinea faciei can mimic seborrheic dermatitis in this population — a KOH examination is worthwhile whenever the diagnosis is in doubt.^[4] Expect a more prolonged, higher-intensity treatment course, and consider HIV testing in a patient with no established diagnosis and no other explanation for severe or refractory disease (see Diagnosis/Differential and Red Flags/Refer).

Parkinson's disease

Seborrheic dermatitis occurs in roughly two-thirds of patients with Parkinson's disease — substantially more than in controls — and severity tracks Parkinson's disease severity and phenotype, with the akinetic-rigid subtype showing greater seborrheic dermatitis severity than the tremor-predominant subtype in a recent cross-sectional study.^[5] Despite this strong association, regular dermatologic follow-up in this population is often inconsistent, so proactively screening for and addressing seborrheic dermatitis at routine visits is worthwhile rather than waiting for the patient to raise it.^[5]

Reassess within 2-4 weeks of starting a new topical regimen to confirm both improvement and genuine adherence. Set realistic expectations from the outset: seborrheic dermatitis is a chronic, relapsing condition, not one cured with a single course of treatment, and most patients will need an ongoing maintenance strategy — typically an antifungal shampoo or cream continued once or twice weekly — to keep it controlled long-term; once-weekly maintenance antifungal shampoo use has been shown to meaningfully reduce relapse.^[2] Continued or fluctuating disease despite adherence does not necessarily mean the medication has failed outright — the disease's natural, variable course means some fluctuation in control is expected — but it should still prompt reassessment rather than blind escalation.^[1]

Patient education

Every patient (or caregiver, for cradle cap) should leave the visit understanding: seborrheic dermatitis is not caused by poor hygiene and is not contagious;^[6] it is a chronic, relapsing condition best managed with an ongoing, typically low-effort maintenance routine rather than a one-time cure; facial skin needs gentler, more time-limited corticosteroid use than the scalp or body; and postinflammatory pigment change in darker skin is an expected, gradually-fading part of the healing process, not a treatment failure.

1. Confirm the diagnosis first — a presentation that is symmetric/flexural (atopic dermatitis), thickly plaqued with silvery scale (psoriasis/sebopsoriasis), tied to a specific external contactant (contact dermatitis), or annular with an active border (tinea) points away from seborrheic dermatitis; reassess or biopsy rather than simply escalating the same treatment.
2. Confirm genuine adherence and correct technique — inadequate contact time with a medicated shampoo, or inconsistent use, is a common and easily corrected cause of apparent failure.
3. Rule out a secondary bacterial or fungal infection with examination, and KOH microscopy if tinea is a possibility, before assuming the underlying disease has simply worsened.
4. Step up within the site-appropriate ladder in Choose Initial Treatment — from an OTC shampoo to a prescription antifungal shampoo, or from a topical antifungal/low-potency corticosteroid to a topical calcineurin inhibitor or PDE4 inhibitor — before reaching for an oral agent.
5. In an adult with no other explanation for severe or refractory disease, consider HIV testing.
6. Refer to dermatology for genuinely refractory disease, diagnostic uncertainty, or before starting an oral antifungal or isotretinoin course.

• Using a moderate- or high-potency topical corticosteroid continuously on the face for maintenance therapy — a leading cause of preventable atrophy, telangiectasia, and perioral-dermatitis-like eruptions in this condition; step down to an antifungal or a calcineurin inhibitor once controlled.
• Treating seborrheic dermatitis as if it were contact dermatitis, or vice versa — the two have genuinely different mechanisms and treatment strategies; see Recognize the Condition and the separate Contact Dermatitis chapter.
• Using an adult-strength medicated dandruff or tar shampoo on an infant's scalp — cradle cap needs a much gentler approach, and no medicated shampoo is approved for children under 2 years.
• Missing sebopsoriasis or underlying psoriasis in a patient not responding to standard seborrheic dermatitis therapy.
• Overlooking the opportunity to consider HIV testing in an adult with new, severe, or refractory disease and no other explanation.
• Assuming cradle cap needs aggressive scale removal — vigorous picking or scrubbing worsens irritation without speeding resolution.
• Reaching for an oral antifungal or isotretinoin course as an early option rather than reserving it for genuinely severe or topical-therapy-refractory disease.
• Not establishing a maintenance plan once disease is controlled, leading to an entirely avoidable cycle of repeated acute flares and repeated corticosteroid courses.

How to use this table: Doses are adult doses and require patient-specific confirmation (renal/hepatic function, weight, allergy history). Pediatric dosing is weight-based per the current product monograph unless stated. Drug pricing is intentionally omitted. Select any drug name to open its complete Pharmasist Drug Database page.

Scalp — First-Line OTC Shampoos

Applied 2-3 times weekly, left on the scalp at least 5 minutes before rinsing; reduce to once-weekly maintenance once clear.

Scalp — Prescription-Strength / 2nd Line

Reserve for scalp disease inadequately controlled by an OTC shampoo, or for moderate-to-severe/itch-predominant disease.

Face and Body — Topical Antifungals (1st Line)

Preferred first-line agents for facial and body disease, with a more favourable long-term safety profile than continuous topical corticosteroid use.

Face and Body — Topical Corticosteroids (2nd Line, Short Courses Only)

Reserve for faster symptom relief or an inadequate response to a topical antifungal alone; use the lowest effective potency for the shortest effective course, especially on the face.

Steroid-Sparing / Long-Term Maintenance

No corticosteroid-type atrophy risk — genuinely reasonable defaults for chronic facial disease and long-term maintenance, not only fallback options.

Infant Cradle Cap

Gentle, non-pharmacologic care is first-line and usually sufficient; reserve medication for extensive or persistent disease.

Severe/Resistant Disease — Systemic Therapy

Reserve for disease refractory to an adequate topical regimen; dermatology-initiated given the monitoring burden of these agents.