Dandruff, an erythematous, greasy, scaling eruption primarily involving the scalp, is the mildest form of seborrhoeic dermatitis. Erythema and greasy scales are found commonly in the central portion of the face (eyebrows, glabella and nasolabial folds) as well as on the chest. A more florid form, in which the lesions are extensive and the inflammatory reaction intense, is frequently seen as an early cutaneous indicator of HIV infection. Seborrhoeic dermatitis in infants appears as a non-pruritic, erythematous, scaling dermatosis involving mainly the scalp and face.

Pityrosporum yeasts are presumed to play at least a facultative, and possibly a causative role in the development of seborrhoeic dermatitis. Androgens may also be involved since men are affected more frequently than women.

Management

Use of a keratolytic shampoo reduces both the inflammation and scaling. There are many detergent-based suspensions or shampoos available containing active agents such as salicylic acid, coal tar, pyrithione zinc and selenium sulfide.

Since good foaming action is required, the shampoo should be massaged into the scalp and left for at least 2-3 minutes before rinsing.

Preparations containing combinations of sulfur and salicylic acid can also be applied to the scalp and other affected areas. Topical applications of corticosteroids, methylrosanilinium chloride (gentian violet) and/or azoles such as ketoconazole are also reported to be effective.