Dermal testing of vaccines for children at high risk of allergies

Abstract: Vaccinations for children with allergic diseases often need to be postponed or terminated because of the presumed risk of an immediate-type allergic reaction such as anaphylaxis. A new skin test protocol for predicting allergic reactions using the vaccine itself and the following stepwise vaccination method were developed and tested. Intradermal tests using 1:10 and 1:100 diluted measles vaccine indicated that the former was superior to the latter because a positive reaction against 1:10 diluted vaccine was found in 28.6% of 49 patients with severe allergic diseases including bronchial asthma, atopic dermatitis, food allergies and allergies to two or more allergens with high levels of IgE, as compared with the reaction against 1:100 diluted vaccine in 10.2% of the patients. Patients negative for 1:10 skin tests were safe from the following full-dose vaccine shots. Three patients showed very strong local reactions against measles vaccine, and avoided receiving the following full-dose shot. Positive reactions to skin tests of 1:10 diluted vaccine were found in 11 patients, who were given stepwise vaccinations. Three patients had adverse reactions, and two of them had been negative for 1:100 skin tests. In the case of influenza vaccine, skin tests were again more sensitive to 1:10 than to 1:100 diluted vaccine, because 3 out of 14 patients with positive reactions showed immediate-type adverse reactions against the following stepwise vaccinations, and 1 of them was negative for the 1:100 skin test. Moreover, the results of the skin prick test (undiluted vaccine) and the intradermal skin test (1:10 diluted vaccine) indicated that the latter was more useful in both cases of measles (54 patients) and influenza vaccine (69 patients). Overall, the skin test using 1:10 diluted vaccine was the more suitable for predicting an immediate-type reaction to measles and influenza vaccinations. Patients having negative 1:10 skin tests can be expected to show no adverse reactions to the remaining injections and even the positive subjects will complete the course of vaccine doses by the stepwise method. [Copyright &y& Elsevier]