Synopsis
Recognise infant and adult seborrhoeic dermatitis across skin tones, distinguish common mimics, use antifungal and anti-inflammatory treatment by site, and plan relapse prevention.
- Adult seborrhoeic dermatitis affects scalp, eyebrows, nasolabial folds, ears and central chest with scale and erythema, lighter or darker change.
- Cradle cap is usually self-limited and gently managed; an unwell infant, widespread eruption or growth failure needs paediatric assessment.
- Ketoconazole shampoo reduces scalp Malassezia: use twice weekly for two to four weeks, leave three to five minutes, then once every one to two weeks for prevention.
- Ketoconazole 2% cream can be applied once or twice daily for two to four weeks to adult facial or body disease, then intermittently for maintenance.
- Use only a short course of mild topical corticosteroid for troublesome inflammation on face or folds; repeated potent facial use causes avoidable harm.
- Patchy hair loss, broken hairs or a boggy plaque is not simple dandruff and requires assessment for tinea capitis.
- For Seborrhoeic dermatitis, document body sites, severity, sleep and function, recent treatment, infection features and what the patient can realistically apply each day.
- In Seborrhoeic dermatitis, reassess the diagnosis when a well-used, correctly potent regimen fails rather than repeatedly intensifying treatment without examining adherence, exposure and mimics.
Key red flags
Erythroderma, fever, failure to thrive, severe eye involvement, extensive disease with immunosuppression, neurological decline or treatment-resistant atypical plaques warrants broader assessment.
Tender boggy scalp swelling, pustules, lymphadenopathy or hair loss suggests inflammatory tinea and risks permanent scarring.
Investigation priorities
Confirm a sebaceous-zone pattern and look for hair-shaft or nail clues to alternatives.
Management branches
Dandruff or seborrhoeic scalp inflammation occurs without alopecia, kerion or systemic illness.
- Use ketoconazole 2% shampoo twice weekly for two to four weeks, massaging into wet scalp and leaving for three to five minutes before rinsing.
- Add a short site-appropriate anti-inflammatory scalp preparation when itch and inflammation remain prominent after scale control.
- Once controlled, use ketoconazole shampoo every one to two weeks and review adherence or diagnosis if no improvement by four weeks.
Key medicines
Ketoconazole 2% shampooAdults and adolescents wet hair and scalp, lather, leave for three to five minutes and rinse; use twice weekly for two to four weeks, then once every one to two weeks.Avoid eye contact and stop for significant irritation or hypersensitivity; review diagnosis if not clear by four weeks and taper prolonged topical steroid while introducing shampoo.
Ketoconazole 2% creamAdults apply to affected and immediately surrounding skin once or twice daily for two to four weeks; intermittent once-weekly maintenance may then be used.Keep from eyes, check excipient irritation and reconsider diagnosis after four weeks without improvement; extensive or immunocompromised disease may require specialist review.