Chronic idiopathic and chronic autoimmune urticaria: clinical and immunopathological features of 68 subjects.

Skin tests with autologous serum elicit an immediate wheal-and-flare response in about 30-50% of chronic idiopathic urticaria subjects, suggesting that an autoimmune mechanism might be involved in the pathogenesis of this disease. The aim of the present work, involving 68 subjects with chronic idiopathic urticaria, was to distinguish between the serum-positive and serum-negative cases and highlight the clinical differences between the two groups on the basis of the Breneman scale score. We also tried to correlate the finding of a positive response to the autologous serum skin test with other autoimmune diatheses or fully developed autoimmune disorders. Our results did not demonstrate any significant differences between the two groups with regard to mean age, sex distribution, angioedema and mucosal/cutaneous atopy. However, all subjects with positive autologous serum skin test presented more severe clinical features than serum-negative subjects. We found no differences between the two groups in the incidence of autoimmune disease.