Use of cephalosporins in a patient with possible cephalosporin allergy

* To select a cephalosporin based on R1 or R2 side chains, refer to the UpToDate topic on the allergy evaluation for immediate cephalosporin reactions, including skin testing and cross-reactivity with other beta-lactam antibiotics.
¶ Safe performance of graded challenges for immediate drug allergy are discussed in the UpToDate topic on the allergy evaluation for immediate cephalosporin reactions, including skin testing and cross-reactivity with other beta-lactam antibiotics.
Δ Desensitization protocols should be performed by allergists and are discussed in the UpToDate topic on rapid drug desensitization for immediate drug hypersensitivity.
◊ A concentration of 20 mg/mL can be used (for prick testing and full strength intradermal testing) for all cephalosporins, except cefepime, which should be tested at 2 mg/mL. Inclusion of the culprit cephalosporin adds certainty to the results of testing if the result is positive to the culprit drug.
§ If use of aztreonam or carbapenems is desired, refer to UpToDate content in the topic on the allergy evaluation for immediate cephalosporin reactions. If use of penicillins is desired, refer to UpToDate algorithm on use of penicillins in a patient with possible cephalosporin allergy.
¥ If the reaction to the culprit drug was life-threatening, some experts give the selected cephalosporin using a desensitization procedure even if skin testing is negative, because the negative predictive value of cephalosporin skin testing is not well defined.