Changing forms of juvenile pityriasis rubra pilaris--a case report.

Pityriasis rubra pilaris (PRP) is a rare disease affecting both males and females. The aetiology is unknown, but it has an ill-defined relationship with psoriasis. Within the spectrum of PRP certain disease patterns are recognized, and regarded by many as helpful prognostic indicators. Griffiths has suggested a clinically based classification based on a series of 98 patients seen at St John's Hospital, London between 1950 and 1972 (Table 1). Classical type 1 PRP is an erythematous squamous disorder typically showing follicular hyperkeratosis, perifollicular erythema and sharply demarcated islands of unaffected skin. The palms and soles become hyperkeratotic and often exhibit a characteristic orange hue. Type III PRP is the juvenile counterpart of classical type I PRP. The following case report describes a patient who presented with type III PRP but later went on to develop the type IV or circumscribed, juvenile onset PRP.