[Clinico-immunological and allergological characteristics of urticaria caused by pyrazolone derivatives]

The authors describe the results of clinical, allergological and immunological examination of 35 patients with urticaria caused by pyrazolone derivatives. Clinically, the patients with pyrazolone-induced urticaria were marked by chronic diseases requiring the prolonged and frequent intake of the analgesics, pyrazolone derivatives. The allergological examination of the 35 patients with pyrazolone-induced urticaria showed that only one of the patients had pollenosis, 6 patients had IgG-mediated reactions to egg protein and one patient to penicillin. For specific diagnosis of drug allergy use was made of the natural leukocyte migration test in vivo according to A. D. Ado. The test appeared positive with analgin in all the 35 patients suffering from pyrazolone-induced urticaria. It represents a simple and accessible method for specific diagnosis of drug allergy both in inpatients and in those visiting allergological rooms at the polyclinics. The immunological examination made with the aid of the histograms demonstrated an appreciable reduction in the content of D-phagocytosing neutrophils. The latter fact might explain the presence of multiple chronic foci of infection in patients with pyrazolone-induced urticaria. Such patients manifested a decrease in C3 that might be related to immediate activation of the alternative pathway of complement by pyrazolone derivatives.