Abstract

SEMEDO, Filipa; CRUZ, Cíntia; TOMAZ, Elza  and  INACIO, Filipe. One-day-only drug provocation test in beta-lactam non-immediate hypersensitivity reaction - Diagnostic efficacy. Rev Port Imunoalergologia [online]. 2019, vol.27, n.4, pp.279-288. ISSN 0871-9721.  https://doi.org/10.32932/rpia.2020.01.022.

Background: Drug provocation tests (DPT) are the gold standard in the diagnosis of beta-lactam hypersensitivity. However, no standardization exists concerning the protocols used between centers, raising the question if a full-course DPT would increase the effectiveness of the allergy workup. Objective: To evaluate the diagnostic efficacy of a 1-day-only DPT with beta-lactam antibiotic in a group of patients with suspected non-immediate hypersensitivity reaction to these drugs. Methods: From the 111 consecutive patients referred to the Allergy and Immunology Department of Centro Hospitalar de Setúbal for suspected beta-lactam hypersensitivity from January 2012 to January 2017, 56 had history of nonimmediate reactions. After completing a 1-day-only DPT with the culprit drug, 54 experienced no symptoms and the DPT were considered negative. Afterwards, an effectiveness questionnaire was administered to assess if patients had been prescribed and received beta-lactams after the negative DPT. Results: Of the total of 54 patients with excluded diagnosis of beta-lactam hypersensitivity with DPT, 24 answered that had been prescribed with beta-lactams during the considered follow-up period. Out of those, 79.2% affirmed that had received the antibiotic and hadn´t suffer from any symptoms of hypersensitivity, confirming the exclusion of drug allergy. The remaining patients did not get the therapy because the lack of confidence in the result. Conclusions: According with the retrospective analysis of our group of patients with suspected non-immediate hypersensitivity reaction to beta-lactams with a negative DPT, it was confirmed that 1-day-only DPT protocol  was totally effective in the diagnostic exclusion, which questions the utility of long course protocols.

Keywords : Beta-lactam; drug hypersensitivity; drug provocation test; non-immediate reaction.

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