Analysis of the Safety of Drug Allergy Workups in a Spanish University Hospital: Drug Characteristics, Type of Reaction, and Patients’ Age at the Initial Assessment

Abstract

<b><i>Introduction:</i></b> The drug provocation test (DPT) is the gold standard for the drug allergy workup; however, it is not free from severe adverse reactions. Our aim was to obtain robust data that predict a reaction during or after the DPT at the first contact with the patient in the allergy outpatient clinic. <b><i>Methods:</i></b> The population of this cross-sectional study comprised all patients undergoing a drug allergy workup (clinical assessment, specific IgE, or skin tests, or DPT) at University Hospital Fundacion Alcorcon in 2016. DPTs were performed until therapeutic doses were reached, and late reactions were checked. The clinical disorders assessed in our study were classified mainly as absence of allergic reactions, morbilliform rash, urticaria, anaphylaxis, and other cutaneous disorders. <b><i>Results:</i></b> Physicians from the Allergy Unit programmed drug allergy workups in 977 patients (median age, 52 years; women, 64.54%). DPTs were not performed for 165 drugs involved in the reactions. Patients who did not undergo DPT were older than patients who did (positive or negative) (<i>p</i> = 0.0001). Positive DPT results were detected in 6.00% of DPTs performed, and most were for amoxicillin and metamizole (15–25% each). Multinomial logistic regression showed that positive reactions were more probable after DPT if the same clinical disorder was diagnosed at the first visit, including the episodes not considered allergic episodes (OR = 0.2, <0.01), except for anaphylaxis, which favored not performing DPTs (OR = 11, <i>p</i> < 0.001). <b><i>Conclusion:</i></b> We conclude that clinical practice in the diagnosis of drug allergy in our Allergy Department is safe, without over-diagnosis.

Drug Allergy Alert System in a Spanish University Hospital: Description and Dynamics of Use

“…Once again, these figures are similar to ours for drug alerts. We found a correlation between the number of allergy alerts by drug and pharmacologic group and the number of drug allergy diagnoses made in the Allergy Outpatient Clinic of HUFA in 2016 [23]. Data from our drug allergy alerts system indicate that the distribution of drug allergy at our institution is similar to that of the general population, despite the large number of false drug allergy alerts we recorded.…”

“…While we did not assess how many patients with drug allergy alerts confirmed a drug allergy, we did know the percentage of positive drug allergies in our institution. Only 27.12% of patients seen at our Outpatient Allergy Clinic for suspicion of drug allergy were eventually diagnosed with drug allergy in 2016 [23]. Therefore, drug allergy alerts are probably a very sensitive tool for reporting drug allergy, albeit at the cost of many false-positive drug alerts.…”

How Far Are We From Achieving Delabeling of False Penicillin/ß-Lactam Allergy Alerts? A Population Problem

“…Gray [28] and Blumenthal et al [29] reported a small increase in mortality risk (hazard-ratio, 1.08 and 1.14, respectively) in patients labeled as allergic to ß-lactams or other, non-ß-lactam antibiotics. These findings should affect only 5% of cases labeled as penicillin allergy, that is, patients with true allergy [26,30].…”