Laboratory tests in chronic urticaria.

One hundred twenty-five patients with chronic urticaria were evaluated with 11 commonly recommended laboratory and radiologic procedures. Abnormal studies were obtained in 26 (20.8%) of these patients, but the majority of these abnormalities were evident from the initial history and physical examination. These results indicate that, with the possible exception of sinus roentgenograms, these laboratory studies are not likely to be helpful in the evaluation of chronic urticaria unless there are suggestive findings in the history and physical examination. The yield and equivalent charge of diagnosis for each procedure used was also analyzed.