Cutaneous polyarteritis nodosa associated with HLA-B39-positive undifferentiated spondyloarthritis in a Japanese patient.

We present the case of a 43-year-old man diagnosed with HLA-B39-positive spondyloarthritis who developed cutaneous lesions consistent with cutaneous polyarteritis nodosa (CPN). Previous studies indicated an elevated incidence of HLA-B39 in HLA-B27-negative Japanese patients with spondyloarthritis. This case suggested that CPN may also occur in association with forms of HLA-B39-positive spondyloarthritis. The rarity of this association is emphasized. Therapy with corticosteroid and methotrexate improved both the cutaneous lesions and the clinical symptoms of spondyloarthritis.