[Cutaneous necrotizing vasculitis in a patient with Behcet's disease; mimicking polyarteritis nodosa].

A 25-year-old-man was referred with an approximately 1-year history of recurrent fever, tonsillitis, testicular pain and testicular swelling in June 2009. He also complained of visual disturbance, some erythema nodosum (EN) like lesions on his lower extremities and oral aphthous ulcerations for 5 months. Opthalmological consultation confirmed retinochoroiditis, and ultrasonography revealed epididymitis. A biopsy of the EN like lesion showed a necrotizing vasculitis of the small and medium-sized vessels with septal panniculitis in the subcutis. The laboratory findings revealed an elevation of CRP and positive HLA-B51. He was diagnosed with incomplete Behcet's disease according to the Japanese criteria (1987). After the initiation of the therapy with 10 mg/day of prednisolone, his symptoms promptly ameliorated. In our case, although epididymitis as well as the histopathological findings suggested polyarteritis nodosa (PN), a diagnosis of BD was established on the basis of other contemporaneous findings. Necrotizing vasculitis as a cutaneous manifestation in patients with BD has been rarely reported. However, BD and PN, including cutaneous PN, have rarely described in conjunction. Therefore, we propose that PN-like necrotizing vasculitis might be the subtype of BD.