Erythrodermic pityriasis rubra pilaris treatment: Two case reports and literature review.

Pityriasis rubra pilaris (PRP) is a rare inflammatory dermatosis characterized by hyperkeratotic follicular papules and erythematous-desquamative plaques that tend to progressively evolve into erythroderma. Treatment is challenging given that international guidelines are not available and large-scale trials do not exist. Traditionally, many topical and systemic drugs had been used as consolidated agents; recently, biologicals are gaining increasing importance, promisingly dominating the therapeutic scenario ahead. Herein, we present a case series showing the "past" and the "future" therapeutic approaches to erythrodermic PRP, one case treated with acitretin and nb-UVB phototherapy combination, while the other with ustekinumab, performing also a throughout literature review.