Affects sebaceous (greasy) zones – face, scalp, centre of chest, skin folds (neck, groin).  Often nappy rash. V common (includes dandruff!).  Inside, outside and around ears can be affected.  Eyelids can be affected (blepharitis).

Babies get transient type – cradle cap (scalp) and nappy area, clears after a few months.  In adults, affects face (esp around nose and ears) and can affect chest and upper back. Can lead to hair loss but more usually cosmetic concerns.

Thought to be caused by overgrowth of Malassezia yeast.  Can be severe in HIV.

Differential is psoriasis.  Scales in psoriasis are thicker and whiter – unusual for face to be affected.

Treatment

For cradle cap in babies, usually enough just to use daily mild shampoo and gentle brushing.  Shampoo may make it worse if the diagnosis is actually atopic dermatitis!  Failing that, coconut oil (NOT olive oil, which has potential to damage skin, apparently) or other moisturizer left in overnight or applied just before bath.

For scalp, Zinc pyrithione, selenium or ketoconazole shampoo (but only licensed for older children).  Leave 5-10 mins before rinsing.  Descaling treatment available – coconut oil and salicylic acid, needs hours.

For body, moisturizer, topical steroids+antifungal eg Canesten HC, Trimovate.

For blepharitis, use baby shampoo to lift flakes.

In adults, anti -androgens.