Comprehensive allergy work-up is mandatory in cystic fibrosis patients who report a history suggestive of drug allergy to beta-lactam antibiotics

BACKGROUND In the general population, reports on suspected ß-lactam hypersensitivity are common. After a drug allergy work-up at best 20% of the selected patients are positive. However, these considerations have not been explored in cystic fibrosis patients for whom antibiotics are even more crucial. METHODS The study, part of the Drug Allergy and Hypersensitivity (DAHD) cohort, was performed in the regional cystic fibrosis center of Montpellier, France. After identifying patients with a clinical history suggestive of drug allergy to ß-lactams, a complete drug allergy work-up, was carried out according to the EAACI recommendations. RESULTS Among the 171 patients involved, 23 reported clinical manifestations potentially compatible with a drug allergy to ß-lactams. After performing the complete drug-allergy work-up, 7 were considered as drug hypersensitive (3 had positive skin tests, 1 a positive provocation test, 3 declined the tests). Excluding the latter 3 patients with incomplete drug allergy work-up, the rate of proven drug allergy was 2.3%. CONCLUSIONS Drug allergy to ß-lactams in cystic fibrosis patients is of importance. A full drug allergy work-up is mandatory in case of suspicion, because ß-lactam responsibility is often ruled out.