Medical thermography in evaluation of results of skin testing by prick test method in patients with IgE-mediated allergic diseases

Abstract

Objective — to study the aspects of use of medical thermography to evaluate the results of skin testing with allergen solutions in patients with allergic rhinitis, atopic asthma and acute allergic urticaria.Materials and methods. During our study, 40 patients with bronchial asthma and/or allergic rhinitis and/or acute allergic urticaria were examined using a skin prick-test with solutions of diagnostic allergens, followed by visual and thermographic evaluation. The study was open-ended, comparative. Skin testing was performed by standardized prick-test method with domestic allergens manufactured by ME Immunolog (Vinnytsya, Ukraine). Immediately after the visual assessment, an instrumental evalua­tion was performed using a thermograph with a locked image in the memory of the device for further processing.After the initial admission and testing procedure, the antihistamine preparation of bilastine was administered at an average recommended daily dose of 20 mg one tablet per day. After three days (72 hours), all patients were retested with a prick-test method and its visual and thermographic evaluation was performed to determine the degree of suppression of the skin reaction by an antihistamine drug.Results and discussion. Analyzing the comparison of results of visual and thermographic measurements of papule size, we found a high coefficient of correlation between test scores (r = 0.9), but the difference between papule sizes averaged 1.6 mm. However, when analyzing the results, the coincidence of visual analysis by the allergist and thermographic measu­rement accounted for only 70 % of cases.Conclusions. As a result of the analysis and further statistical processing, it was found that the average diameter of the papules of the positive test during the re-examination after taking bilastine decreased by 55.6 % (95 % CI 0.50—0.59). At the same time, in the vast majority (87.2 %) of patients (95 % CI 0.83—0.91), the positive test disappeared completely.