Cutaneous vasculitis in psoriasis.

Cutaneous vasculitis has been reported as a complication of pustular psoriasis but not of plaque type psoriasis. In the past 5 years we have observed 3 patients who in the course of their psoriasis developed cutaneous vasculitis. Two of these patients also had severe psoriatic arthropathy and were on etretinate during the onset of vasculitis. However, there was no deterioration or recurrence of vasculitis whilst the patients were maintained on the drug. The third patient with vasculitis had not received retinoids. No obvious causes of vasculitis were found in the 3 patients and the rash resolved spontaneously without any systemic complications though surgical amputation was necessary in one case. None of the cases required immunosuppressive therapy and the skin lesions mostly resolved spontaneously. The mechanisms that triggered off vasculitis in our patients are unknown but are likely to be immune-mediated.