Ineffectiveness of tumor necrosis factor-α blockers and ustekinumab in a case of type IV pityriasis rubra pilaris

Treatment of pityriasis rubra pilaris (PRP) may be difficult since no standardized therapeutic approach has been established. Recently, tumor necrosis factor-α (TNF-α) blockers have been demonstrated to be favorable in the management of recalcitrant PRP. The authors report a case of a patient who presented a type IV PRP or circumscribed, juvenile type. Such a condition follows an unpredictable course, presenting with diffuse, palmoplantar keratoderma and sharply-demarcated areas of follicular hyperkeratosis on the elbows and knees. Treatment with all available TNF-α inhibitors and ustekinumab did not prove to be helpful. The authors suggest that circumscribed variants of PRP could respond to therapy in ways different from classical PRP.