What is the risk of using a cephalosporin in a patient with a penicillin allergy?

Practical management of antibiotic allergy in adults

This review looks at the main issues around immediate hypersensitivity and the role and limitations of testing. The majority of literature on antibiotic hypersensitivity relates to β-lactam antibiotics, mainly because of the heavy usage of this class of drugs. Concerns around cross-reactivity always worry clinicians, particularly in the emergency situation. Reasonable data now exist in relation to β-lactam antibiotics and derivatives, which enable appropriate risk management to be undertaken. The available literature for other classes of antibiotics is also discussed.