Erythroderma secondary to pityriasis rubra pilaris

A 67 yr old woman† presented in the department of Dermatology at Hospital Regional Universitario of Malaga, Spain, in November 2017 with a three-week history of generalized redness and scaling of the skin, hyperthermia and severe pruritus. The disease began with red and orange plaques on the head and chest spread caudally with islands of sparing (Fig. 1). On clinical examination, palmer waxy keratoderma (Fig. 2)was observed. Dermoscopic evaluation showed orange perifolicullar keratotic papules surrounded by erythema with some linear vessels (Fig. 3). No visceral enlargement or adenopathies were noted. All laboratory blood tests were within normal ranges. Skin biopsy demonstrated irregular acanthosis and diffused compact hyperkeratosis with spotted parakeratosis (Fig. 4). With the diagnosis of pytiriasis rubra pilaris, the patient was treated with acitretin with improvement in the erythroderma after 16 weeks.Fig. 1: Orange plaques on the trunk (A) and on the legs (B) with islands of sparing.Fig. 2: Waxy keratoderma of palms.Fig. 3: Orange perifollicular papules surrounded by erythema with some linear vessels under dermoscope (arrows).Fig. 4: Histology showing acanthosis and diffuse compact hyperkeratosis (red arrow) with spotted parakeratosis (black arrow) (Hematoxylin and eosin, ×200).Erythroderma has multiple aetiologies. This disease can represent a serious problem, and hospitalization may be required. One must look for the specific findings of the underlying disease, start the correct treatment and avoid the systemic complications of erythroderma.