Postzoster eruptions: Granuloma annulare, granulomatous vasculitis and pseudolymphoma

Various postzoster skin rashes have been reported as granuloma annulare and pseudolymphomas and have occurred in patients with and without leukemia. The cases of five patients who had postzoster skin lymphogranuloma lesions are reported, and the relation to treatment and the clinical course are reviewed. Monoclonal antibody and pathology studies were performed. Typical T-cell-predominant granuloma annulare of the skin was found in two cases, and T-cell-predominant lymphogranuloma with some large atypical B cells was identified in a third case of a dermatomal postzoster eruption. A patient with lymphatic leukemia had vascular invasion by lymphocytes with focal granulomatous vasculitis and in addition a dermatomal granuloma. Another patient showed dermatomal skin tumors of lymphoplasmacytoid cells. No consistent relationship between eruption and previous treatment with corticosteroids or acyclovir therapy for herpes zoster was demonstrated. ACTH therapy healed the skin lesions and stopped the zoster neuralgia symptoms in two patients. Postzoster granuloma annulare, granulomatous vasculitis, and lymphoid tumors occur in the skin of some patients and are unrelated to previous treatments for herpes zoster. These conditions are readily treated with conservative therapy. The lesions are benign and do not imply systemic occurrence or progression of lymphoid malignancy.