B Sachs1, T Al Masaoudi, H F Merk, S Erdmann. 1. Department of Dermatology and Allergology, Rheinisch-Westfälische Technische Hochschule Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany. bcsachs@tiscalinet.de
Abstract
BACKGROUND: Amino-penicillins are a major cause of delayed-type reactions to penicillins. OBJECTIVES: The aim of this study was to establish a diagnostic approach for the characterization of the individual penicillin-specific polyclonal lymphocyte reactivity in order to detect side chain-specific sensitization to amino-penicillins. Patients can then be advised to undergo a tolerance test with safe penicillins instead of provocation with culprit penicillins for confirmation of penicillin allergy. METHODS: We investigated penicillin-specific polyclonal lymphocyte reactivity in nine patients with delayed-type reactions to amino-penicillins by a combined in vivo (patch, prick and intracutaneous tests with delayed readings) and in vitro (lymphocyte transformation test, LTT) approach. RESULTS: A combination of LTT and skin tests improved the sensitivity for the characterization of penicillin-specific polyclonal lymphocyte reactivity and allowed the detection of three different patterns of lymphocyte reactivity. Four patients showed a side chain-specific sensitization to amino-penicillins in vivo and in vitro and were advised to undergo tolerance tests with safe penicillins. Two patients agreed and were exposed to parenteral benzyl-penicillin and oral phenoxymethyl-penicillin which they tolerated without complications. CONCLUSIONS: These data suggest that a combined in vivo and in vitro approach is helpful for the detection of side chain-specific sensitization to amino-penicillins. Patients with such sensitization are very likely to tolerate safe penicillins, thereby expanding their therapeutic options when antibiotic treatment is required.
BACKGROUND:Amino-penicillins are a major cause of delayed-type reactions to penicillins. OBJECTIVES: The aim of this study was to establish a diagnostic approach for the characterization of the individual penicillin-specific polyclonal lymphocyte reactivity in order to detect side chain-specific sensitization to amino-penicillins. Patients can then be advised to undergo a tolerance test with safe penicillins instead of provocation with culprit penicillins for confirmation of penicillinallergy. METHODS: We investigated penicillin-specific polyclonal lymphocyte reactivity in nine patients with delayed-type reactions to amino-penicillins by a combined in vivo (patch, prick and intracutaneous tests with delayed readings) and in vitro (lymphocyte transformation test, LTT) approach. RESULTS: A combination of LTT and skin tests improved the sensitivity for the characterization of penicillin-specific polyclonal lymphocyte reactivity and allowed the detection of three different patterns of lymphocyte reactivity. Four patients showed a side chain-specific sensitization to amino-penicillins in vivo and in vitro and were advised to undergo tolerance tests with safe penicillins. Two patients agreed and were exposed to parenteral benzyl-penicillin and oral phenoxymethyl-penicillin which they tolerated without complications. CONCLUSIONS: These data suggest that a combined in vivo and in vitro approach is helpful for the detection of side chain-specific sensitization to amino-penicillins. Patients with such sensitization are very likely to tolerate safe penicillins, thereby expanding their therapeutic options when antibiotic treatment is required.