Cutaneous polyarteritis nodosa: a report of 16 cases with clinical and histopathological analysis and a review of the published work.

Sixteen cases of cutaneous polyarteritis nodosa referred to our Department from 1985 to 2003 were studied clinically and histopathologically. Laboratory data, treatments and clinical courses were also evaluated retrospectively. All cases had nodules and/or indurated erythemas on their lower extremities. All cases showed necrotizing vasculitis of small muscular arteries in the subcutaneous tissues and/or occlusion of those arteries histopathologically. Fifteen cases also had accumulation of plasma protein in vessels of the dermis and subcutaneous tissues. Laboratory data showed high activity of platelets and coagulation in some cases. Eleven cases had been effectively treated with non-steroidal anti-inflammatory drugs. Eight cases were observed for at least 5 years (the longest for approximately 19 years) and had good prognoses and no systemic involvement. Cutaneous polyarteritis nodosa seems to be a benign disease, and differs from systemic polyarteritis nodosa although their histopathological features are common. Cutaneous polyarteritis nodosa might involve local dysfunction of the circulation from the dermis to the subcutaneous area. A review of the published work shows that the cause(s) of most cases of cutaneous polyarteritis nodosa is unknown, that no controlled trials for treatment of cutaneous polyarteritis nodosa compared to polyarteritis nodosa have been reported, and that no definitively effective therapy for cutaneous polyarteritis nodosa has been established.