| In the case of patients with a history of immediate reactions to BLA and planned administration of another BLA, skin testing (skin prick test and – if available for parenteral administration – intradermal test) with the planned BLA, in vitro diagnostics where necessary, as well as stepwise drug provocation shall be performed. The range of BLA to be avoided should be kept as narrow as possible. |
| In the case of patients with a history of immediate reactions to penicillin in whom the use of another BLA is indicated as part of acute emergency treatment and if skin tests are unavailable, fractionated drug provocation tests with a non-aminocephalosporin, aztreonam, or carbapenem under appropriate supervision should be considered after risk/benefit analysis of the individual case. The same applies to the use of a non-side chain-related cephalosporin in patients with a history of immediate reactions to cephalosporins and to the use of aztreonam if there is a history of immediate reactions to all BLA except ceftazidime. Patients with a history of reactions to ceftazidime should only be exposed to aztreonam following negative skin test with the drug. |
| In the case of a history of immediate reactions or proven allergy to a BLA and urgently indicated use of the suspected BLA or a BLA with a high risk of cross-reactivity, desensitization needs to be considered (see Sect. “Decensitization (tolerance induction)”) after a decision has been taken on the individual case. |
| In patients with mild delayed reactions (uncomplicated exanthema) to penicillin but urgently requiring another BLA – and allergy testing not possible in a timely manner – the use of a non-aminocephalosporin, carbapenem, or aztreonam is justifiable (albeit associated with an acceptable risk of a similar delayed reaction). The same applies to patients with mild delayed reactions (uncomplicated exanthema) to a cephalosporin in terms of the use of a non-side chain-related cephalosporin, as well as to patients with mild delayed reactions to a BLA other than ceftazidime and the use of aztreonam. If patients have previously reacted to ceftazidime, skin testing should be performed before using aztreonam. |
| Patients need to be informed about the risk of experiencing similar delayed reactions and instructed on how to respond if a delayed reaction occurs. |
| If the symptoms of reactions in the patient history cannot be reliably classified (anaphylaxis/urticaria versus uncomplicated exanthema), an approach that assumes prior anaphylaxis shall be selected in the case of an acute need for treatment. It is important when performing allergy testing during a symptom-free interval to establish whether a reaction is immediate or delayed. |
| In the case of a previous reaction to an aminopenicillin, no aminocephalosporin should be used without prior skin testing. The same approach applies to substances in the side chain-related group: cefuroxime, ceftriaxone, cefotaxime, cefodizime, and ceftazidime with each other. |
| In the case of previous hypersensitivity reactions to combination preparations containing beta-lactamase inhibitors, hypersensitivity to the beta-lactamase inhibitor is also possible. Therefore, if available, skin testing for this is recommended, as well as provocation testing if necessary. |
| All recommendations are subject to an individual benefit–risk assessment. |
