Necrotizing mesenteric vasculitis after longstanding cutaneous polyarteritis nodosa.

We describe a 21-year-old woman with cutaneous polyarteritis nodosa (PAN) who developed necrotizing mesenteric vasculitis 6 years after the onset of skin disease. Repeated investigation during that 6-year interval failed to reveal any evidence of systemic PAN. We were unable to wean the patient from prednisone or completely control her skin disease with topical and systemic therapy, including supersaturated potassium iodide, dapsone, azathioprine, methotrexate or plasmapheresis before the development of the mesenteric vasculitis, which responded to cyclophosphamide and prednisone. Development of visceral vasculitis after long-standing cutaneous PAN has very rarely been reported.