scalp rashes
The most common scalp symptoms are: Itch, Soreness, Scale/flaking, Pustules/sores
| Pityriasis amiantacea | Very thick asbestos-like scale Scale is very adherent to hair shafts Subsequent diagnosis usually seborrhoeic dermatitis or psoriasis Pityriasis amiantacea    |
| Tinea capitis | Irregular scaly plaques with moth-eaten hair loss May have inflammatory, abscess-like kerion Hairs are easy to extract Positive microscopy and culture of scrapings and extracted hair Sometimes, fluorescence on Wood light examination   |
| Psoriasis | Any age, most > 15 yearsMay be localised or diffuse May be isolated to scalp or involve other body sites Check ears, elbows, knees, nails Circumscribed erythematous scaly plaques Large, usually white scale Poor response to topical therapy (various shampoos, calcipotriol, potent topical steroids) Hair loss uncommon, but when occurs, loose hair shafts can be extracted from scaly plaques    |
| Seborrhoeic dermatitis | Infants or > 13 yearsMay be localised or diffuse May be isolated to scalp or involve other body sites Check ears, eyebrows, nasolabial folds Thin salmon-pink flaky plaques, sometimes annular Small flakes of yellow or white scale Good, temporary, response to topical therapy (ketoconazole shampoo, mild topical steroid) Hair loss uncommon, but when occurs, loose hair shafts can be extracted from secondarily infected, oozy plaques Seborrhoeic dermatitis of scalp    |
| Atopic dermatitis | Any age especially children In infants, may overlap with seborrhoeic dermatitis Usually diffuse and very itchy Involves other body sites Scalp rash rarely prominent Check elbow flexures, popliteal fossae, eyelids Ill-defined erythematous blistered or dry plaques Lichenification Dryness rather than loose scale Good response to properly applied topical therapy (potent topical steroid)Hair loss rare Atopic dermatitis of scalp    |
| Discoid lupus erythematosus | Localised erythematous, scaly and hairless, scarred plaques; often multiple May be isolated to scalp or involve other body sites Check nose, cheeks, ear concha Lichen planopilaris Localised, sometimes erythematous bald plaques Perifollicular scale Lonely hairs Discoid lupus erythematosus of scalp    |
| Head lice | Usually, but not always, young child Look for lice on the nape of neck and behind ears Nits are adherent white grains on hair shafts Red-brown spots on the skin are due to excreted digested blood. Excoriations, hair pulled out   |
| Dermatitis herpetiformis | Scalp a common site, also shoulders, buttocks elbows, knees Intensely itchy solitary or multiple blisters, rarely seen, as scratched |
| Scalp folliculitis |  itchy or painful follicular pustules and scratched erosions No hair loss Poor response to topical steroid May improve with long-term oral tetracyclineScalp folliculitis |
| Folliculitis keloidalis nuchae |  Males with dark coarse hair Occipital scalp Few pustules Firm follicular papules Larger keloid scars with sparse hairs |
| Dissecting cellulitis |  Also known as perifolliculitis capitis abscedens et suffodiens Associated with acne conglobata, hidradenitis suppurativa Crusting, inflammatory nodules, large fluctuant cysts, with hair loss |
Seborrhoeic dermatitis of infancy Seborrhoeic dermatitis of infancy | = ‘cradle cap’ if affects scalp; ‘nappy rash’ if affects napkin area- causes: not clearly defined may have rel with yeast (malassezia sp) features: within first 3 months, not itchy, red/yellow greasy scale, usually scalp / cheeks / folds of neck / axillae / folds of elbows + knees. In the napkin area it can be prone to candida mx: General: keep areas dry + clean, bathe in warm water & pat dry if using lotion use something like cetaphil, keep skin exposed to as much air as possible, change wet or soiled nappies often, rub scales of cradle cap gentle with baby oil, for mild areas on body apply zinc cream Medication: – Scalp 🡪 ketoconazole shampoo (ie: nizoral) if infant 1-2% salicyclic acid in aqueous cream applied to scalp overnight & mild baby shampoo off next day – Face, flexures & trunk 🡪 ketoconazole cream 2% once or twice daily or 1% hydrocortisone – Napkin area 🡪 1% hydrocortisone + 2% ketoconazole (ie: hydrozole cream) prognosis: most children clear by 18months  |