Negative predictive value of drug provocation tests in children.

Background: The negative predictive value of the drug provocation test is important for both the patient and the physician. However, in children, this predictive value is unresolved.

Methods: The study included patients who had drug provocation test with a suspected drug and was diagnosed as 'not allergic to the drug'. Three months after allergy workup, the patients were contacted and asked for reexposure to the tested drug. Patients who have reported reactions during reexposure were reevaluated with skin tests and drug provocation.

Results: During the study period, 217 provocations were performed to 203 patients. Of these, 163 patients (80.3%) with 175 negative drug provocation tests could be contacted. Ninety-one (52%) of the 175 cases reported to use the tested drug again, and 11 (12%) of these cases declared that they had a new reaction. Two of the eleven cases refused reevaluation. Nine cases were evaluated by drug allergy workup. Two of the nine cases were classified as allergic after retests. Collectively, the negative predictive value was 95.6% (87 of 91 cases) for all drug challenges.

Conclusions: The negative predictive value of the drug provocation test is abundant in children; however, negative drug provocation tests do not necessarily predict tolerance for the drug.