Evaluation of IR
Before ST, SIgE testing was carried out by fluoroimmunoassay (CAP system, Thermofisher Diagnosis, Uppsala, Sweden R). Results of 0.35 kUA/l or more were considered positive11.
The determinants used for ST were penicilloyl-polylysine (PPL) (5x10-5mol/l), minor determinant mixture (2x10-2mol/l), and PG (104UI/ml). If negative, we proceeded to the graded administration of penicillin V until achieving the therapeutic dose5,19. If tolerated well, we evaluated the response to AX if this drug was involved alone or in combination with CLAV; if tolerance was still good, we proceeded to ST with CLAV to test if this was the culprit, and then finally to a DPT with AX-CLAV. If a cephalosporin was involved, we tested first with common determinants of PG, and if negative, we proceeded to cephalosporin (first ST and if negative, DPT when indicated).
DPT was performed in a single-blind, placebo-controlled way as described elsewhere18, under strict hospital surveillance with emergency room facilities. We gave escalating doses of the drug at intervals of 30 min to 60 min until reaching the weight-adjusted therapeutic dose5. BLs were administered orally at the following doses: 5 mg, 25 mg, 50 mg, 75 mg, 100 mg, and 250 mg, with a final observation period of at least 1 h after the last dose administered.