Sensitivity of autologous serum skin test for chronic autoimmune urticaria

Using undiluted fresh serum by both skin prick test and intradermal injection (0.05 mL and, when negative, 0.1 mL), we have tested 55 consecutive subjects with CIU, about half of whom were positive for anti-thyroid antibodies (ATA). The two groups were quite homogenous in terms of age and associated atopy, as evaluated by the clinical history and the positive results of skin prick test or specific immunoglobulin E to the most common inhalant and/or food allergens. The only difference that we found was that females were significantly more prevalent in the ATA-positive group. The autologous serum prick test was negative in all the patients, whereas the intradermal test scored positive (diameter of the weal ≥ 3 mm) in only 5 (9%), unexpectedly higher in ATA-negative (15%) than in ATA-positive (4%) patients