Asthma, Family History of Drug Allergy, and Age Predict Amoxicillin Allergy in Children

Background: Suspected adverse reactions to amoxicillin are common, but there are no known factors that can predict amoxicillin allergy in children. In addition, methods used for the diagnosis of amoxicillin allergy are not standardized and their role in diagnosis is not clear. Objective: To identify predictive factors and to assess the role of skin test in the diagnosis of amoxicillin allergy in children. Methods: Children with a history of immediate (excluding anaphylaxis) or nonimmediate reactions to amoxicillin were tested by skin prick test, followed by oral graded challenge with amoxicillin. Clinical characteristics of the reaction before and after the challenge were recorded, and data of personal and relatives' drug allergies and atopy were collected for statistical analysis. Results: Skin prick tests followed by an oral graded challenge with amoxicillin were performed on 133 children. The skin test result was not of clinical value because it was negative in all children. Three children (2%) had an immediate reaction and 7 children (5%) had a nonimmediate reaction. Asthma (odds ratio [OR], 0.12; 95% CI, 0.017-0.869; P =.03), family history of drug allergy (OR, 0.12; 95% CI, 0.026-0.613; P =.01), older age at reaction (OR, 0.837; 95% CI, 0.699-1; P =.05), and angioedema (OR, 0.22; 95% CI, 0.043-1.12; marginally significant at P =.069) were associated with reduced chance to pass the oral challenge. Conclusions: Skin prick test did not contribute to the diagnosis of amoxicillin allergy. The presence of asthma, family history of drug allergy, and older age at reaction can be used as predictive factors for true amoxicillin allergy in children.