1 - Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, E.P.E., Rua Jacinta Marto, Lisboa, Portugal
2 - CEDOC, Integrated Pathophysiological Mechanisms Research Group, Nova Medical School, Campo dos Mártires da Pátria, 1150-190 Lisboa, Portugal.
- Reunião Internacional, apresentação sob a forma de Póster com discussão em 2018th European Academy of Allergy and Clinical Immunology, Munique -Alemanha, 26 a 30 de Maio, 2018
Resumo:
BACKGROUND: Local anaesthetics (LA) are widely used and, even though a high number of adverse drug reactions (ADR) have been reported, true hypersensitivity reactions (HR) are extremely rare. The aim of the study was to assess the usefulness of the cutaneous tests in the investigation of the suspected HR to LA.
METHOD: Retrospective analysis of patients’ records with suspected LA allergy over a 10-year period (2008-2017). HR to LA was considered when intradermal (IDT) or challenge tests (CT) were positive.
RESULTS: A sample of 57 patients was studied; the majority were females (n=48), with a median age of 47.5 years (min 9 years, max 83 years). In 29 patients there was 1 suspected LA, in 10 there were 2 LAs, in 1 patient 3 LA and in 17 the suspected drug was unknown. Lidocaine was the main suspected drug (n= 21), followed by articaine (n=10) and mepivacaine (n=7). The most frequently described reactions were mucocutaneous symptoms referred by 47% of the patients and non-specific symptoms (30%). Nine patients referred respiratory symptoms and 6 anaphylaxis. Cutaneous tests were performed in 55 patients using the implicated drug(s) plus alternative(s). All skin prick tests (SPT) performed were negative. Two patients had positive IDT with the suspected LA (3.6%), both with previous reported anaphylaxis. From the 57 patients, 5 refused the CT and only one of them had positive IDT with the suspected LA. CT were carried out in 52 patients, using the suspected LA in case of negative IDT or with an alternative LA in the positive ones. Two of these patients did not perform previous SPT nor IDT and in the CT it was used the culprit drug. Three of the 52 patients had at least a positive CT, but none of the reactions were more severe than the previous ones. An alternative LA was always found, another amide in 2 cases and procaine in the other one. In this particular case, the patient reacted towards all 4 amides tested (IDT or CT positives).
CONCLUSION: In our sample, the suspected allergy was confirmed in only 4 of the 57 patients (7%), suggesting that true HR to LA is rare. A negative IDT does not exclude positive CT. Nevertheless, the severity of the reactions did not seem to be greater than the previous one. Based on these, the investigation of allergic reactions to LA should always include skin tests in severe cases, like anaphylaxis, and it could be bypassed in mild to moderate reactions.
Palavras Chave: Local anaesthetics; drug allergy