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.