2.Improving drug allergy label accuracy by supervised safety- and protocol-driven evaluation.
Chiara Jiamin CHONG ; Karen Jui Lin CHOO ; Kheng Yong ONG ; Vivian TAN ; Janet Beng Neo KHOO ; Kavitha Garuna MURTHEE ; Ibrahim Muhammad HANIF ; Chaw Su NAING ; Haur Yueh LEE
Annals of the Academy of Medicine, Singapore 2022;51(11):677-685
INTRODUCTION:
Drug allergies are often self-reported but of unknown accuracy. We carried out a prospective study to examine the utility and safety of formal allergology evaluation, and to identify factors associated with accurate drug allergy labels.
METHOD:
All patients who underwent drug allergy evaluation in our clinic during the study period were recruited. Baseline demographics, characteristics of index hypersensitivity reaction and outcomes of evaluation were recorded.
RESULTS:
A total of 331 patients from March 2019 to June 2021 completed drug allergy evaluation to index drugs of concern. There were 123 (37%) male patients, and the mean age was 49 years (standard deviation 17). There were 170 beta-lactam antibiotics, 53 peri-operative drugs, 43 others, 38 non steroidal anti-inflammatory drugs, and 27 non-beta-lactam antibiotic evaluations. Index reaction occurred within 5 years in 165 (50%) patients, with latency of less than 4 hours in 125 (38%) patients. The most common index reactions were rash, angioedema and urticaria. There were 57 (17%) evaluations stratified as low risk, 222 (67%) moderate risk, and 52 (16%) high risk based on multidisciplinary consensus. Allergy label was found to be false (negative drug evaluation) in 248 (75%) patients, while 16/237 (7%) skin tests, 44/331 (13%) in-clinic graded challenge, and 23/134 (17%) home prolonged challenges were positive (true drug allergy). The most common evaluation reactions were rash and urticaria. No cases of anaphylaxis were elicited.
CONCLUSION
Seventy-five percent of drug allergy labels are inaccurate. Risk-stratified, protocolised allergy evaluation is safe. Prolonged drug challenge increases the sensitivity of drug allergy evaluation and should therefore be performed when indicated.
Humans
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Male
;
Middle Aged
;
Female
;
Prospective Studies
;
Drug Hypersensitivity/epidemiology*
;
Exanthema
;
Urticaria
;
Monobactams
Result Analysis
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