DIAGNOSIS OF PENICILLIN, AMOXICILLIN, AND CEPHALOSPORIN ALLERGY - RELIABILITY OF EXAMINATION ASSESSED BY SKIN TESTING AND ORAL CHALLENGE

The specificity of pediatrician-diagnosed allergy reactions to penicil lin, amoxicillin, and oral cephalosporins, which was based on contempo raneous examination of the patient, was evaluated by an elective skin testing program. Children and adolescents (n = 247) experiencing an ad verse reaction to penicillin, amoxicillin, and/or an oral cephalospori n sufficient to lead to the recommendation to avoid further use were e nrolled. Skin testing with penicillin G, commercial benzylpenicilloyl phosphate, penicillin minor determinate mixture, ampicillin, cefazolin , cefuroxime, and ceftriaxone was performed according to the suspected drug allergy followed by an oral challenge, repeat testing, and prosp ective follow-up if no reactions were observed. Overall, 84 (34.0%) of 247 patients had an IgE-type reaction on skin testing or oral challen ge. Twenty-seven (32%) of 85 suspected penicillin reactions, 53 (34%) of 156 suspected amoxicillin reactions, and 13 (50%) of 26 suspected c ephalosporin reactions were shown to be IgE mediated. Positive skin te sts were observed in 20 patients with non-IgE-type clinical adverse re actions, including 15 patients with only a pruritic polymorphous rash. No reactions to oral challenge were severe after negative skin testin g. One hundred sixty-three patients received multiple treatment course s with beta-lactam antibiotics after a negative skin testing procedure and three (1.8%) had adverse IgE reactions, all of which were mild. P hysician-diagnosed allergic reactions to beta-lactam antibiotics based on patient examination at the time of the reaction is more accurate t han patient history alone but still overestimates the rate of possible true allergy in 66% of patients. Elective penicillin, amoxicillin, an d cephalosporin skin testing and oral challenge protocols are necessar y to identify patients not at risk.