Pityriasis amiantacea refers to a reaction pattern on the scalp where large adherents are attached to the growing hairs and overlap like tiles on a roof. The abnormality may be localised and confined to a small patch or widespread involving the entire scalp. The underlying scalp is often moist and inflamed. The condition may occur on its own or may be associated with inflammatory disorders such as seborrhoeic dermatitis and psoriasis or with underlying dermatophytosis (tinea capitis).