Two Cases of Pityriasis Rubra Pilaris after Cyclosporine Treatment / 대한피부과학회지

ABSTRACT

Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory papulosquamous disease of the skin. Its exact pathogenesis and incidence are not yet known. Clinically, it presents as palmoplantar keratoderma, hyperkeratotic follicular papules, and plaques. PRP can be diagnosed by histopathological examination, and the characteristic histopathological features include alternating orthokeratosis and parakeratosis, hypergranulosis, psoriasiform acanthosis with short and broad rete ridges, thick suprapapillary plates of the epidermis, and superficial perivascular inflammatory cell infiltrates. There are six subtypes of PRP based on clinical manifestations and age of onset. PRP is known to respond to acitretin, and treatment with other medications such as isotretinoin, methotrexate, and biologics results in symptomatic improvement. We present two cases of patients who developed type 2 and type 4PRP following treatment with cyclosporine.