The relationship between pityriasis rubra pilaris and inflammatory arthritis: Case report and response of the arthritis to anti–tumor necrosis factor immunotherapy

Pityriasis rubra pilaris (PRP) refers to a group of erythematous, scaling dermatologic conditions that have been associated with seronegative arthritis. We report a case of polyarthritis in a young man with PRP in which magnetic resonance imaging suggested an entheseal-based pathology for the joint disease. The arthritis, but not the skin condition, demonstrated dramatic response to anti–tumor necrosis factor immunotherapy.