Accuracy in diagnosis of allergy to β-lactams

Table 1 Diagram for diagnosis of penicillin allergy

β-lactam	Skin prick test (mg/ml)	Intradermal (mg/ml)	Provocation test (mg)
Penicillins	PPL 5×10^-5 mmol/l; MDM 2×10^-2 mmol/l; penicillin G 20-25^a	As SPT	5, 25, 100, 250, 500
Aminopenicillins (amoxicillin, ampicillin, cloxacillin) Cephalosporins	PPL 5×10^-5 mmol/l; MDM 2×10^-2 mmol/l; penicillin G 20-25^a	As SPT	5, 25, 100, 250, 500
Oral (cefaclor, cefadroxil, cefixime, cefuroxime)	2-100	2^a	5, 25, 125, 500
Intravenous (cefazolin, ceftriaxone, ceftazidine)	2-100	2^a	5, 25, 100, 500, 1,000

Diagnosis was supported by skin test (ST) (skin prick and intradermal test) [5, 6], and if STs were negative by a single-blind drug challenge test (DChT) with increasing doses of the suspected drug [3, 4] every 60 minutes until the usual daily dose was administered or symptoms occurred (some of the symptoms previously described were present) [2]. If symptoms appeared more than 3 hours after the last dose of the DChT, a new DChT was proposed and scheduled. PPL, major determinant of penicillin (Diater Lab, Madrid, Spain); MDM, minor determinant mixture of penicillin (Diater Lab); SPT, skin prick test. ^aFrom Torres and colleagues [7].

ISSN: 1364-8535