Herein, we describe the treatment of 2 patients with suberythrodermic pityriasis rubra pilaris (PRP) with guselkumab, a specific interleukin 23 (IL-23)p19 inhibitor.
Patient 1 (male, 65 years of age) and patient 2 (male, 75 years of age) presented at our hospital with an 8- to 12-week history of generalized erythema and pruritus. Neither of the patients had a history of skin diseases. When referred to our specialty clinic, both men reported impaired quality of life (dermatology life quality index score, 15 of 30 and 19 of 30 for patient 1 and patient 2, respectively). The static physician global assessment score was 5 of 5 in both men, and the involved body area was 95% in patient 1 and 98% in patient 2 (Figure 1). Patient 1 reported severe itching (peak pruritus was 9 of 10 on a numeric rating scale), whereas patient 2 only felt intermittent light itching (peak pruritus was 3 of 10 on a numeric rating scale). Both patients presented with a salmon-colored erythroderma interspersed with well-distinguishable areas of unaffected skin, that is, so-called nappes-claires (Figure 2). Histological analysis revealed acanthosis with broad rete ridges, a confluent hypergranulosis, as well as a hint of alternating orthokeratosis and parakeratosis. In the dermis, biopsy results revealed a superficial perivascular lymphocytic infiltrate. Given the clinical and histopathological findings, a diagnosis of PRP was made in both cases. Treatment with oral and topical corticosteroids for several months in both patients, as well as acitretin in patient 1, remained ineffective, despite use for 10 weeks. Oral retinoids were contraindicated in patient 2 owing to severe renal insufficiency (Kidney Disease Improving Global Outcomes stage G4).