ABSTRACT
Background: Hypersensitivity to beta-lactam (BL) antibiotics is one of the most frequent reported drug allergies. In our population, it is common to find labels of BL allergy in electronic medical records (EMRs) that have not been assessed. The objective of our study was to detect patients with beta-lactam allergy labels in their EMRs and to assess how many of them are false after a correct diagnostic evaluation. Methods: A multicentre prospective study was performed with patients labelled as allergic to BLs in their EMRs in the previous 5 years. Demographical and clinical data, as well as variables regarding the BL allergy label and the characteristics of the index reaction from clinical history and EMRs, were recorded. Then, diagnostic assessments including clinical history, skin tests (STs), and drug provocation tests (DPTs) were conducted in order to confirm or exclude the diagnosis of BL allergy. Results: A total of 249 patients completed the study, of which 160 (64.3%) were women with a median age of 57 years (interquartile range [IQR], 45-68). The most frequent BL allergy labels detected were for penicillin (124), amoxicillin/clavulanic acid (61), and amoxicillin (54). Of the 204 patients who underwent STs, 20.1% were positive. DPTs were performed in 224 patients, showing good tolerance in 87.1% of cases. After the allergy diagnosis work-up, 186 patients (74.7%) were diagnosed as non-allergic to BL antibiotics. Conclusion: In our study population, the number of patients labelled as allergic to BLs in their EMRs was similar to that in previously published studies, with proportions near to 75%-80% being falsely labelled as allergic to BLs.
ABSTRACT
Background: The guidelines for the treatment of chronic spontaneous urticaria (CSU) recommend adding omalizumab to the treatment of patients with uncontrolled disease despite four-fold doses of second-generation antihistamines (AH). On the contrary, some studies revealed that omalizumab was effective without concomitant AH and several authors suggest tapering off AH when CSU is controlled with omalizumab. Objectives: The aim of our study was to evaluate the use of AH during treatment with omalizumab in patients with CSU in real clinical practice. Materials & Methods: This was a multicentre cross-sectional and observational study conducted by the Catalan and Balearic Chronic Urticaria Network (XUrCB) based on a cohort of 298 CSU patients treated with omalizumab. Results: In total, 23.5% of our patients decided themselves to stop taking AH during omalizumab treatment. The ratio of patients with CSU without concomitant inducible urticaria and the percentage of patients with a good response to omalizumab (UAS7≤6 and/or UCT ≥12) were higher in those who stopped taking AH. Conclusion: More studies are required to identify the phenotypic characteristics of patients responding to omalizumab as monotherapy in order to avoid overtreating with AH. Our study suggests that patients with CSU without concomitant inducible urticaria and those who achieve a good response to omalizumab tend to be controlled by omalizumab without AH. In order to establish guidelines on how to stop AH, further evidenced-based studies are required.
