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Background and Objective: Amoxicillin-clavulanic acid (AX-CL) is the most consumed ß-lactam antibiotic worldwide. We aimed to establish the different phenotypes of ß-lactam allergy in patients reporting a reaction to AX-CL and to investigate the differences between immediate and nonimmediate onset., Methods: We performed a cross-sectional retrospective study at Hospital Clínico San Carlos (HCSC), Madrid and Hospital Regional Universitario de Málaga (HRUM), Málaga, Spain. We included patients reporting reactions with AX-CL who underwent the allergy workup between 2017 and 2019. Data on the reported reaction and allergy work-up were collected. Reactions were classified as immediate and nonimmediate with a 1-hour cut-off., Results: The study population comprised 372 patients (HCSC 208, HRUM 164). There were 90 immediate reactions (24.2%), 252 nonimmediate reactions (67.7%), and 30 reactions with unknown latency (8.1%). Allergy to ß-lactams was ruled out in 266 patients (71.5%) and confirmed in 106 patients (28.5%). The final main diagnosis in the overall population was allergy to aminopenicillins (7.3%), to CL (7%), to penicillin (6.5%), and to ß-lactams (5.9%). Allergy was confirmed in 77.2% and 14.3% of immediate and nonimmediate reactions, respectively, with a relative risk of 5.06 (95%CI, 3.64-7.02) for an allergy diagnosis in those reporting immediate reactions. Only 2/54 patients with a late-positive intradermal test (IDT) result for CL were diagnosed with CL allergy., Conclusion: Allergy was diagnosed in a minority of the study population. However, given that it was diagnosed 5 times more frequently in patients reporting immediate reactions, this classification proved useful for risk stratification. Late-positive IDT results for CL have no diagnostic value. Therefore, the late IDT reading for CL could be removed from the diagnostic work-up.

Background and Objective: The prevalence of hypersensitivity reactions to radiological contrast media (RCM) is increasing owing to the improved performance of diagnostic and therapeutic tests that require RCMs. Objective: We carried out a year-long real-life observational study to prospectively evaluate patients referred to the allergy department from primary care, the emergency department, and other specialties with suspected moderate-to-severe RCM hypersensitivity reactions., Methods: To study the costs of evaluating RCM hypersensitivity reactions, we systematically recorded direct and indirect costs., Results: Sixty-nine patients with previous reactions to RCM were evaluated in the allergy department from June 1, 2017, to May 31, 2018.Total direct health care costs were €10 715.84, with a mean (SD) cost per patient of €155.30 (77.08). Specifically, direct non-health care costs reached €1605.42 (mean, €23.27 [41.14]), and indirect costs were €6490.85 (mean, €94.07 [110.61]). In summary, the total cost was €18 812.11, that is, a mean cost of €272.64 (164.77)., Conclusion: Our study shows that the costs of an elective evaluation of hypersensitivity reactions to RCM are low, thus confirming that correct and safe management of affected patients are cost-effective. Therefore, our efforts should be directed toward ensuring the necessary logistics.

The clinical history is the cornerstone of the doctor´s work. When assessing patients consulting for a suspected hypersensitivity reaction to a drug, the details collected in the patient´s clinical history are essential when deciding which tests to perform and for making recommendations about which drugs the patient should avoid and which can be taken. This area is especially important today, since many patients are labeled as allergic to drugs, especially penicillins, without this being the case. This article reviews the importance of the clinical history in a patient with a hypersensitivity reaction to a drug and considers which data should be collected. Likewise, a record-based model is proposed to help standardize the clinical history.

The controlled drug provocation test (DPT) is currently considered the gold standard for the diagnosis of drug allergy. Adverse drug reactions (ADRs) are an increasingly common presenting complaint in both primary and specialized care. In Spain, ADRs are usually assessed via the allergology department, which rules out immunological mechanisms in up to 90% of cases. An adequate approach to ADRs clearly impacts the costs and efficacy of the treatments prescribed by other specialists. Consequently, if we did not use DPTs, patients would require more expensive, more toxic, and less effective treatments in many cases. In recent years, many new drugs have been developed. This document is intended to be a practical guideline for the management of DPTs according to the vision of the Spanish Allergology Society. The diagnostic work-up begins with a detailed clinical history. Skin tests are only useful for some medications, and in most cases the diagnosis can only be confirmed by DPT. Although cross-reactivity is common, DPTs can confirm the diagnosis and help to find an alternative drug. Programmed individualized patient management based on the type of drug to be studied and the patient´s comorbidities usually enables a solution to be found in most cases.

The consumption of quinolones as first-line treatment has increased in recent years, leading to an increase in the incidence of hypersensitivity reactions (HSRs) to this antibiotic group. Both diagnosis and management of HSRs to quinolones are complex and controversial. These practical guidelines aim to provide recommendations for effective clinical practice. The recommendations were drafted by an expert panel that reviewed the literature regarding HSRs to quinolones and analyzed controversies in this area. Most HSRs to quinolones are immediate and severe. The risk for HSRs is higher in patients who report allergy to ß-lactams, moxifloxacininduced anaphylaxis, and immediate reactions than in patients who report reactions to quinolones inducing other symptoms. The usefulness of skin tests in diagnosing HSRs to quinolones is controversial, with sensitivity and specificity varying between studies. Most in vitro tests are produced in-house, with no validated commercial options. The basophil activation test has proven useful for diagnosing immediate reactions, albeit with diverse results regarding sensitivity. Drug provocation testing is currently the gold standard for confirming or excluding the diagnosis and for finding safe alternatives, although it is contraindicated in patients with severe reactions. Cross-reactivity between quinolones has proven controversial in several studies, with the lowest cross-reactivity reported for levofloxacin. Desensitization may be considered in allergy to quinolones when no other alternatives are available.

Background: The study of perioperative drug reactions remains a major challenge for both diagnosis and therapy. The lack of a standard assessment of allergy to general anesthetics and of data establishing the true value of skin tests for most drugs used in induction and maintenance of anesthesia, as well as the lack of commercially available reagents for in vitro tests, renders the study of these reactions problematic. The aims of this study were to provide a diagnostic protocol for drug challenge testing with general anesthetics, to establish an etiological diagnosis that is as specific as possible, and to determine the predictive value of skin tests., Methods: Twenty-nine patients with perioperative drug reactions were included in the study from November 2008 to December 2018., Results: We confirmed the high negative predictive value of the tests (96%-100%) in the case of propofol, rocuronium, and fentanyl. To our knowledge, this is the first study to describe drug challenge testing with general anesthetics and, therefore, to establish the true negative predictive value of skin tests, which leads to a definitive diagnosis and safer surgery., Conclusions: After assessing risks and benefits and considering the importance of this group of drugs, we conclude that drug challenge testing with general anesthetics is necessary. We propose a protocol for perioperative drug reactions that enables us to make a highly accurate etiological diagnosis with minimum risk for the patient.

The disease caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ie, coronavirus disease 2019 (COVID-19), has become a global pandemic since it was first reported in Wuhan, China in December 2019. Its severe clinical manifestations, which often necessitate admission to intensive care units, and high mortality rate represent a therapeutic challenge for the medical community. To date, no drugs have been approved for its treatment, and various therapeutic options are being assayed to address the pathophysiological processes underlying the clinical manifestations experienced by patients. New and old drugs administered as monotherapy or in combination to immunologically compromised patients may favor the development of adverse drug reactions, including drug hypersensitivity reactions, which must be identified and managed accordingly. Given the lack of herd immunity and the high rate of viral contagion, new cases are expected to emerge in the coming months. Thus, the probability of more adverse reactions or even new clinical manifestations may increase in parallel. Allergists must receive updated information on these treatments, as well as on the management of possible drug hypersensitivity reactions.