Pityriasis rubra pilaris – a retrospective single center analysis over eight years

Background: Pityriasis rubra pilaris (PRP) is a rare papulosquamous dermatosis. We evaluated evaluate co‐morbidities, complications, and outcome of treatment regimens. Patients and Methods: This is a retrospective study at an academic teaching hospital. We analyzed all patients with the definite diagnosis of PRP seen since 2001. Epidemiologic data, co‐morbidities, response to and course during treatment were investigated. Results: We identified 10 PRP‐patients (6 men, 4 women), mean age 56.4 years, with type I (n = 9) and type IV (n = 1). Three patients had internal co‐morbidities (atrial fibrillation with cardiac insufficiency, dilated cardiomyopathy, diabetes mellitus). Two patients needed psychiatric treatment because of depression. PRP caused ectropium (2 ×), diffuse effluvium (1 ×), and stenosis of the outer ear canal (1 ×). We did not observe a spontaneous remission. Among 9 patients with PRP type I, five were treated with acitretin (two of them as Re‐PUVA), and two with methotrexate (in one patient combined with fumaric acids). Systemic corticosteroids were not effective. One patient was treated with infliximab i.v., 5 mg/kg body weight. Starting with the first application, inflammatory activity decreased and erythema got paler. The treatment was well tolerated. Conclusions: PRP type I is a severe, chronic inflammatory dermatosis responding hesitantly to classic systemic therapies. Tumor necrosis factor‐α antagonists are an effective treatment option for difficult cases.