[Exploration of 112 children suspected of amoxicillin allergy. Indications and efficacy of oral provocation test].

BACKGROUND

One to 10% of treatments using betalactams, particularly synthetic penicillin, are complicated by allergic reactions, usually cutaneous, and not easily imputable to immunologic sensitization in children.

PATIENTS AND METHODS

The aim of this study was to identify, using cutaneous and biological tests, those from a group of 112 children suspected of amoxicillin allergy (evidenced by rash) who were actually sensitized, and to confirm the absence of allergy in others by an oral provocation test (OPT) associated to a long-term survey. The cutaneous tests were made by prick test and intra-dermo reaction (IDR) with Allergopen and with amoxicillin or amoxicillin + clavulanic acid. The biological tests included examination for penicillin and amoxicillin antibodies by using various techniques including enzyme-linked immunosorbent assay (ELISA) immunoglobulin G (IgG) and IgE, FARR, radioallergo sorbent test (RAST) and a histaminoliberation. When these tests were negative, an OPT with the suspected antibiotic was subsequently performed.

RESULTS

Thirty-nine children (36.4%) confidently presented at least one positive cutaneous test (38 Allergopen, ten amoxicillin); 25 biological tests were positive (16 ELISA IgE, one ELISA IgG and eight histaminolibarations), seven times with negative cutaneous test. Forty-five children were judged to be sensitized to amoxicillin, with only one who subsequently took amoxicillin again. Among the 67 others, 52 received an OPT, six of them with moderate cutaneous reactions. Fifty-one (45.5%) children were allergic and 46 (41%) were allowed to take amoxicillin again; 17 did, one of them with a benign cutaneous reaction.

CONCLUSION

Efficacy and safety of this type of investigation seems clear; it will have to be confirmed by other studies.