Pityriasis rubra pilaris – eine seltene entzündliche Dermatose mit vielen Facetten

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease. There are 6 distinct subtypes with striking clinical variation in both children and adults. Basic elements noted across all subtypes include follicular keratotic papules that evolve to distinct, well-demarcated, scaling plaques of various sizes with typical reddish-orange hue. More generalized subtypes tend to show intervening areas of unaffected skin, known as "islands of sparing" (nappes claires), which represent a characteristic feature. PRP shows a broad spectrum of presentations ranging from mild manifestations confined to extremities to severe disease developing into erythroderma. The present review provides an overview of the current state of knowledge of this hitherto poorly understood dermatosis.