Cystic fibrosis (CF) is a chronic disease for which chronic therapies are required to slow the progression of disease . Patients with CF suffer daily symptoms, frequent exacerbations of pulmonary infection, and an early demise . Chronic airway inflammation and infection are indeed the greatest causes of mortality and morbidity in patients with CF, the resulting lung damages being the main cause of death [1, 3, 4]. Antibiotics are typically used for early, intermittent infection, with the goal being to eradicate the pathogen . Antibacterial therapies are instituted empirically and are individualized based on both patient’s factors (severity of exacerbation, frequency of exacerbation, recent courses of anti-infectives) and pathogen factors (previously isolated pathogens and in vitro predicted antibiotic susceptibilities) .
The French registry on CF reported that, in 2007, more than 75% of the 4806 patients who underwent a common cytobacteriologic examination of the sputum (93.5% of the CF patients treated in France) were infected by a non-commensal bacteria (mainly Staphylococcus aureus and Pseudomonas aeruginosa) and, amongst them, 1837 (35.7%) had received at least one course of antibiotics during the previous year .
The frequent use of antibiotics in patients presenting with CF is often associated to hypersensitivity clinical manifestations, commonly leading to patients being considered allergic to one or more antibiotics, and therefore such drugs being contra-indicate. Thus, the prevalence of drug allergy is reported to be three times greater (6 to 22%) than the one observed in the general population [7–9]. However, as for the general population, it could be suspected that in many cases the clinical manifestation was misunderstood, and falsely considered as a drug allergy [10, 11].
In the general population, allergy to betalactams (BLs) is the most frequent cause of drug reaction, mediated by specific immunological mechanisms . Such reactions may be induced by all BLs currently available . Such an assumption has to be true even in patients with CF, who are much more exposed to these molecules than the general population. The allergy work-up involves careful history-taking followed by a drug provocation test (DPT) when skin tests are negative . If skin tests and/or DPT are positive, a different BL is often found as an alternative.
The present study aimed to assess the prevalence of patients presenting clinical manifestations considered as a drug allergy to BLs, one of the most commonly used antibiotics in CF patients. Moreover, the study also looked for the prevalence of proven drug allergy after a thorough drug allergy work-up.