125:
Safety of amoxicillin provocation test using the PSU 2-step challenge in children with a history of non-immediate reactions
Saturday, March 3, 2018
South Hall A2 (Convention Center)
Vanlaya Koosakulchai, MD, Duangdee Wantanaset, MD, Wipa Jessadapakorn, MD, Pasuree Sangsupawanich, MD, PhD, Araya Yuenyongviwat, MD, Thatchai Wirodwanich, MD
RATIONALE: A drug provocation test (DPT) is the gold standard for the diagnosis of a drug allergy in non-immediate reactions. Although patch testing, delayed reading intradermal test (IDT), and lymphocyte transformation test can be useful in children with non-immediate reactions, none have been standardized. The aim of this study is to evaluate the safety of the amoxicillin provocation test without skin test using the PSU 2-step challenge in children with a history of non-immediate reactions.

METHODS: Open drug provocation tests were performed in children with a history of nonimmediate cutaneous reaction without systemic symptoms. The PSU 2-step challenge is composed of 2 doses of amoxicillin with a 30-minute interval in the absence of antecedent skin testing. Provocation was continued for 4 days.

RESULTS: Thirty-one children had a median age of 5.9 years (range, 10 months-15 years) and 74% were male. Twenty-seven subjects (87%) and 4 subjects (13%) reported adverse reactions to amoxicillin and amoxicillin-clavulanic acid, respectively. The reactions were maculopapular rash in 27 (87%) and urticarial rash/angioedema in 4 (13%) children. The median time that elapsed between the suspected reaction and the DPT was 2.7 years (range, 2 months-13.5 years). Only one patient (3.2%) had a reaction during the provocation test, whereas 30 (96.8%) tolerated the culprit drug.

CONCLUSIONS: The PSU 2-step challenge seems to be a safe protocol even in the absence of antecedent skin testing in children with a history of non-immediate cutaneous reaction and without systemic symptoms.