Testing confirms very few parent-reported pediatric drug allergies

Although 7% of questioned parents believed that their child had a drug allergy, testing showed that only 0.05% of these children had a true drug allergy, according to a study published in Annals of Allergy, Asthma & Immunology.

These results indicate that parent statements alone are not enough to diagnose drug allergies in children, Murat Capanoglu, MD, of the department of pediatric allergy and immunology at University of Health Sciences, Ankara Child Health and Diseases Hematology Oncology Training and Research Hospital in Ankara, Turkey, and colleagues wrote.

When the researchers asked the parents of 5,553 children aged 4 months to 17.9 years who had been treated at a tertiary pediatric hospital in Turkey over a period of 6 months due to various health problems if their child had ever developed an allergy after drug use, 389 of them (7%) said that their child had experienced a drug allergy.

The researchers then invited these children to the hospital’s pediatric allergy clinic, where a pediatric allergist evaluated them using the European Network for Drug Allergy (ENDA) questionnaire and found 82 (21.1%) who were compatible with a possible drug allergy, indicating a drug allergy rate of 1.47% for the full population.

The median age of reaction among the children who were compatible with a possible drug allergy was age 2.5 years (interquartile range [IQR], 0.95-5.5). Also, these evaluations occurred at age 4.17 years (IQR, 1.9-7.65), and 45 children (54.9%) were boys.

These patients all had cutaneous symptoms, and four (4.9%) had histories that were compatible with anaphylaxis. Nine (11%) patients had accompanying allergic disease, although none of the patients had any history of severe cutaneous drug reaction.

Drugs suspected of eliciting allergic reactions included antibiotics (81.7%), NSAIDs (9.8%) and antiepileptic drugs (3.6%). Reactions with NSAIDs mostly were immediate, whereas suspected reactions with other drugs mostly were non-immediate.

Next, 72 patients were tested for drug allergy via skin tests, skin prick tests or drug challenge tests based on ENDA recommendations. This testing confirmed drug allergies in three patients, representing 4.2% of those tested and 0.05% of the total studied population.

All three cases were due to beta-lactam group antibiotics, including two caused by ceftriaxone and one caused by amoxicillin-clavulanate. Also, all three of these patients had an accompanying allergic disease.

However, 10 patients with histories compatible with drug allergies were not tested because their parents did not provide consent. These histories included reactions to metamizole, antiepileptics, phenytoin, ceftriaxone and vancomycin, with eight of these patients using alternate drugs without any issues.

Based on these findings, the researchers said that there are drawbacks to basing drug allergy diagnoses on parent statements, as families may consider any reaction that develops with drug use an allergy, leading to unnecessary drug allergy labeling.

When antibiotic allergies are misdiagnosed, the researchers explained, broad-spectrum alternative antibiotics may be used instead. Also, they added, antibiotic resistance may develop, and costs may increase.

Before these patients receive a drug allergy label, the researchers continued, they should be referred to an allergist for an allergic evaluation. Once the drug allergy is confirmed, providers should determine which alternative drugs these patients can use safely for similar indications.

Future studies, the researchers concluded, are necessary to determine how frequently drug allergies truly occur among children.