[A case of pityriasis rubra pilaris associated with rapidly progressive finger joint destruction].

A 40-year-old female noticed edema of the lower limbs in March 1995. Nephrotic syndrome due to membranous nephropathy was diagnosed and administration of high-dose corticosteroids resulted in incomplete remission. Progressively enlarging, red scaling skin lesions developed concomitantly from the scalp to the extremities. Pityriasis rubra pilaris (PRP) was diagnosed in 1996 in the Department of Dermatology at Sapporo Medical University hospital. Various treatments proved ineffective. Arthritis of the finger joints developed in July 1999, and proteinuria recurred in April 2000. She was admitted to our department in August 2000. Physical examination on admission revealed marked swelling of both distal interphalangeal (DIP) joints and the right fourth proximal interphalangeal (PIP) joint. Results of testing for antinuclear antibody, rheumatoid factor, and HLA-B27 were all negative. Radiography of the hands revealed destruction of the DIP and PIP joints where MRI indicated the presence of synovitis. Bone scintigraphy demonstrated accumulation in bilateral metatarso-phalangeal joints and the left sacroiliac joint. Arthritis associated with PRP was diagnosed, as both PRP and psoriasis represent keratinizing disorders of the skin and clinical features in the present case resembled those of psoriatic arthritis. Despite administration of high-dose corticosteroids, destruction of finger joints progressed rapidly. Administration of cyclosporine in April 2002 improved arthritic symptoms. Cases of PRP accompanied by arthritis need to be accumulated to allow analysis of the pathogenesis and clinical picture of this association.