Dermoscopy for discriminating between pityriasis rubra pilaris and psoriasis

Pityriasis rubra pilaris (PRP) is a relatively uncommon entity that often has to be clinically differentiated from other erythematosquamous skin diseases, such as psoriasis. Dermoscopy has already been shown to enhance clinical evaluation of inflammatory skin conditions and dermoscopic patterns of various diseases, including psoriasis, have been documented. In the current manuscript we present the dermoscopic findings observed in two patients suffering from PRP and psoriasis, respectively. The dermoscopic pattern of PRP consisted of round/oval yellowish areas surrounded by vessels of mixed morphology. The latter findings are clearly distinct from the dermoscopic features of psoriasis, which have been extensively investigated previously and are presented also in the psoriatic patient herein. This observation represents an initial indication that dermoscopy could be of value in differentiating between the two entities.