Teicoplanin allergy - an emerging problem in the anaesthetic allergy clinic.

BACKGROUND Anaphylaxis to teicoplanin appears to be extremely rare, with only one confirmed case report worldwide. Two anaesthetic allergy clinics in the UK have received a number of suspected cases referred for investigation, and we present here the first case series of teicoplanin allergy. METHODS We investigated 20 cases of suspected teicoplanin allergy, identified from the two clinics over a period of two years. We devised a set of five criteria to categorize the certainty of their diagnosis. These included: (1) reaction within 15 min of administration of teicoplanin, (2) ≥2 features of anaphylaxis present, (3) positive skin testing or challenge testing, (4) raised serum mast cell tryptase (MCT), (5) alternative diagnosis excluded. Based on these criteria we defined the likelihood of IgE-mediated allergy to teicoplanin as: definite-met all criteria; probable-met criteria 1.2 and 5, plus 3 or 4; uncertain-met criteria 1.2 and 5; excluded- any others. RESULTS We identified 7 'definite', 7 'probable' and 2 'uncertain' cases of teicoplanin allergy. Four cases were excluded. CONCLUSIONS IgE-mediated anaphylaxis to teicoplanin appears to be more common than previously thought. This is true even if only definitive cases are considered. Investigation of teicoplanin allergy is hampered by the lack of standardized skin test concentrations. In some cases, there was a severe clinical reaction, but without any skin test evidence of histamine release. The mechanism of reaction in these cases is not known and requires further study.