Drug provocation tests in patients with a history suggesting an immediate drug hypersensitivity reaction.
BACKGROUND
Drug hypersensitivity reactions are common and can be life-threatening. Confirmation of the diagnosis should be rigorous and based on clinical history and a physical examination, possibly followed by skin tests and drug provocation tests.


OBJECTIVE
To describe the outcome of drug provocation tests in evaluating patients with histories suggesting drug allergy.


METHODS
Retrospective analysis of clinic case series.


METHODS
The department for drug allergy at a university hospital.


METHODS
898 consecutive patients with suspected immediate drug allergy referred to the clinic between September 1996 and August 2001. Patients with severe skin reactions and those with positive results on skin tests for beta-lactams were excluded.


METHODS
Single-blinded administration of increasing doses of the suspected drug, up to the usual daily dose, under strict hospital surveillance.


RESULTS
1372 drug provocation tests were performed using various drugs, including beta-lactams (30.3%), aspirin (14.5%), other nonsteroidal anti-inflammatory drugs (11.7%), paracetamol (8.9%), macrolides (7.4%), and quinolones (2.4%). There were 241 (17.6%) positive drug provocation test results. Drug provocation reproduced the same symptoms, albeit milder and of a shorter duration, in the following patients: 13 (5.4%) with a history of anaphylactic shock, 17 (7.0%) with a history of anaphylaxis without shock, 10 (4.1%) with a history of laryngeal edema, 19 (7.9%) with a history of bronchospasm, 160 (66.4%) with a history of urticaria, and 22 (9.1%) with a history of maculopapular eruption. All adverse reactions were completely reversed by prednisolone, H(1)-antihistamines, and epinephrine as needed.


CONCLUSIONS
Falsely negative results on drug provocation tests may have occurred because of loss of sensitization, rare cofactors not included in the diagnostic procedure, and tolerance induction during provocation.


CONCLUSIONS
Drug provocation tests in individuals with suspected drug allergy performed in carefully controlled settings can confirm drug hypersensitivity.
Messaad
Djamel
D
Hopital Arnaud de Villeneuve, Montpellier, France.
Sahla
Hocine
H
Benahmed
Said
S
Godard
Philippe
P
Bousquet
Jean
J
Demoly
Pascal
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019937:Diagnostic Techniques and Procedures; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016037:Single-Blind Method