Page 13 - Premios_SPAIC-DIATER

Skin tests and challenge-based drug allergy diagnosis:

a retrospective study of patients with confirmed drug allergy

1,3
1,2
A.M. Pereira , M. Couto , M. Pereira , L. Araújo 1,2,4
1,2
1 CINTESIS, Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Portugal
2 Allergy Unit, CUF-Porto Instituto and Hospital, Porto, Portugal
3 MEDIDA, Lda, Porto, Portugal
4 Basic and Clinical Immunology, Pathology Department, Faculty of Medicine, University of Porto, Porto, Portugal
Eur Ann Allergy Clin Immunol 2020;52(2):74-83
DOI: 10.23822/EurAnnACI.1764-1489.107

ABSTRACT
Objectives: To describe clinical manifestations and performed diagnostic workup, focusing on drug challenge tests
(DCT), in patients with drug allergy. Methods: Retrospective study including all patients with skin tests (STs) or DCT-
based drug allergy diagnosis between 01/2014 - 06/2018 in a Portuguese allergy unit. Data were collected from
electronic and paper-based clinical records. Results: We had 75 drug allergy diagnoses. Most index reactions were
mild and ≥ 1 hour after drug intake. Fifty-nine (78%) diagnoses were based on DCTs, all based on multistep protocols
with ≥ 3 predicted steps. Only 10% of the DCT were positive during up-dosing; timing and severity of the index reaction
predicted DCT interruption during up-dosing. Conclusions: Most drug allergy diagnoses were based on multistep DCT.
The identified predictors of DCT interruption during up-dosing can support the development of more personalized
DCTs protocols.
Keywords: Drug allergy, drug challenge test, skin tests, predictors, decision tree.

COLET ÂNEA DOS PRÉMIOS SP AIC–DIA TER 11