Postirradiation Morphea and Subcutaneous Polyarteritis Nodosa: Case Report and Literature Review

OBJECTIVE To describe a case of postirradiation morphea and subcutaneous polyarteritis nodosa occurring simultaneously in a patient and to review the literature on postirradiation autoimmune phenomenon and the potential pathogenesis of such changes. METHODS A 75-year-old woman with breast cancer treated with chemotherapy and radiation who developed postirradiation morphea and subcutaneous polyarteritis nodosa, both inside and outside of the field of radiation, is described. Literature searches were performed on postirradiation morphea and other radiation-related inflammatory cutaneous conditions and the potential pathogenic mechanisms involved. RESULTS Twenty-five cases of postirradiation morphea and 8 cases of postirradiation panniculitis were reported in the literature. Only 3 cases of morphea with distant vasculitis occurring in the same patient have been reported and each of these patients had features suggestive of an underlying connective tissue disease. This is the first case of morphea and subcutaneous polyarteritis nodosa occurring in the same location both inside and outside the field of radiation. CONCLUSIONS Postirradiation morphea is an uncommon condition but is being increasingly recognized. Related phenomena following radiation include postirradiation panniculitis and now postirradiation subcutaneous polyarteritis nodosa. Radiation may be responsible for inducing some of the pathogenic changes seen in scleroderma and other autoimmune diseases. Rheumatologists should be aware of these potential complications of radiation treatment.