Seborrhoeic Dermatitis, Scalp Psoriasis and Hair

Abstract

Seborrhoeic dermatitis was first described by P. G. Unna more than 100 years ago. Its localization on the scalp has often been referred to synonymously with dandruff, and there is little evidence to refuse the concept that it corresponds clinically to severe dandruff. Nevertheless, the lower incidence of seborrhoeic scalp dermatitis, the presence of erythema as a sign of inflammation, considerably more scaling, and the frequent correlation with eczematous lesions of scalp skin or else where on the body are, however, features of seborrhoeic dermatitis which distinguish it from dandruff. Of course, none of these features alone is clearly diagnostic, and seborrhoeic dermatitis as an entity has remained controversial. Whatever the cause, transient alopecia may occur in seborrhoeic scalp dermatitis, particularly in infants (Agache 1986).