Elderly people thought to have an allergy to beta-lactams (BLs) may tolerate the drugs in subsequent exposures due to initial false labeling of allergies, the spontaneous loss of sensitivity to BLs over time or age-related decline in sensitization. A new study published in the Journal of Asthma and Allergy assessed whether older patients with previously confirmed allergies to BLs had lost sensitization and could tolerate these antibiotics.In this study, patients allergic to BLs were divided into two groups; group A – aged 60-79 years, and group B – aged ≥80 years. Clinical history, skin testing, drug challenge tests (DCT) and evaluation of re-sensitization were used to classify participants as showing immediate reactions, non-immediate reactions or tolerance. Thereafter, clinical entities, drugs involved and final outcome by age group were compared.Overall, 565 patients underwent an allergological study. The results revealed that skin manifestations were the most common—anaphylaxis and side chain reactions were more frequent in group A, as were positive DCT. On the other hand, classical benzylpenicillin determinants – benzylpenicilloyl and/or minor determinant mixture, were more frequent triggers in group B. Meanwhile, resensitization after challenge occurred in very few participants.Thus, it was concluded that the risk for allergy to BLs decreases with age; a history of anaphylaxis by BLs is a predictor of positive results in skin tests (ST). It was stated that both, immunoglobin E (IgE) and T-cell-mediated responses can disappear in elderly people who may develop tolerance to these antibiotics.