Pityriasis amiantacea: a case report.

Pityriasis amiantacea (PA) is a papulosquamous condition of the scalp,characterized by asbestos - like thick scales attached to the hair shaft. It is thought to represent a reaction pattern to inflammatory skin disorders like psoriasis, seborrhoeic dermatitis, tinea capitis, atopic dermatitis and lichen planus, rather than a distinctive disease. The scaling may be localised or generalised, depending on the underlying condition and its duration.This report highlights the clinical features of pityriasis amiantacea secondary to atopic dermatitis and the differential features of other papulo-squamous scalp disorders such as scalp psoriasis, seborrhoeic dermatitis and lichen planus.Scalp psoriasis and seborrhoeic dermatitis are the commonest causes of PA as well as the closest differentials hence should be excluded in all cases. The longterm sequelae of PA include scalp fibrosis and permanent hair loss hence should be identified and treated promptly. The management modalities of PA will also be discussed.