A case of resistant pityriasis ribra pilaris responsive to combination acitrentin and ustekinumab.

Pityriasis rubra pilaris is a rare psoriasiform dermatitis. Treatment has been adopted from psoriasis protocols, with topical corticosteroids and systemic retinoids as first-line agents, followed by escalation to biologics for recalcitrant disease. We report a patient with resistant pityriasis rubra pilaris who dramatically improved with acitretin and ustekinumab, a combination not well documented in the literature. The purpose of this letter is to emphasize the potential benefit of dual therapy in patients who fail traditional pityriasis rubra pilaris treatment regimens.