O03 Allergy to penicillins in a pediatric population: reported vs true

• Published in: Archives of disease in childhood Vol. 104; no. 6; pp. e1 - e2
• Main Authors: Elzagallaai, AA, Gill, H, Rieder, MJ
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group LTD 01.06.2019
• Subjects: Allergies; Allergy; Antibiotics; Hypersensitivity; Hypersensitivity (delayed); Hypersensitivity (immediate); Infectious diseases; Lymphocytes; Patients; Pediatrics; Penicillin; Radioallergosorbent test; Risk factors; Toxicity
• ISSN: 0003-9888; 1468-2044
• DOI: 10.1136/archdischild-2019-esdppp.3

BackgroundReported allergy to penicillins is a major clinical problem. Over 10% of parents report drug allergy resulting in higher cost and less than optimum management of infectious diseases.ObjectivesTo determine the relative likelihood of true allergy in patients suspected to have a penicillin allergy and to investigate the risk factors involved. We hypothesized that the vast majority of self-reported penicillin allergies are less likely to be true allergies when proper immunological work up is performed.MethodsPaediatric patients aged 0–18 years presenting to the ADR clinic at the Children Hospital of Western Ontario (CHWO) with suspected antibiotic allergies were included. A retrospective review of charts was conducted to obtain demographic information and results from allergological and in vitro testing. Subjects were evaluated with a radioallergosorbent test (RAST) or the lymphocyte toxicity assay (LTA)/the in vitro platelet toxicity assay (iPTA) depending on whether the history was most consistent with an immediate allergy or a delayed hypersensitivity, respectively. Patients with negative RAST or LTA/iPTA were recommended to undergo confirmatory oral challenge test (OCT).ResultsNinety subjects were identified including 75 with possible penicillin allergy and 10 with suspected allergy to a non-penicillin antibiotic. Five subjects presented with a mixed allergy. Based on the results from RAST, in vitro testing and OCTs, the prevalence of a true allergy in the penicillin group was 6.25% vs. 66.67% in the non-penicillin group (p< 0.001). Patients presenting with severe reactions were more likely to be truly allergic (p< 0.01). In-patients were more likely to present with non-penicillin allergies and were subsequently more likely to have a true allergy (p< 0.001).ConclusionsTrue allergy is very rare in patients with suspected penicillin allergies and can be determined with a proper work-up including OCT. Shorter protocols for the evaluation of these patients would be beneficial.Disclosure(s)Nothing to disclose