Penicillin Drug Allergy Clinical Pathway — All Settings

Allergy Considerations

Rationale for Prescribing Selected Cephalosporins for Penicillin-Allergic Patients*

Patients with a history of "penicillin allergy" actually have an IgE mediated allergy (which should be the main concern for clinicians) in < 10% of cases.

Cephalosporin allergy is primarily related to side chain structure. Cephalosporins that have a side chain structure similar to a penicillin may cross-react, increasing the likelihood of an IgE mediated reaction in penicillin-allergic patients. Cefdinir, Cefpodoxime, Ceftriaxone, Cefazolin and Cefepime [ 1 ] do not have a side chain structure similar to any of the commonly prescribed penicillins, therefore these specific cephalosporins are safe to use in patients with a history of penicillin allergy.

Types of Allergic Reactions to Penicillins and Cephalosporins**

Immediate (within 1-2 h) IgE mediated	Bronchospasm Hypotension Laryngeal edema Local swelling Urticaria
Late (after 24 h)	Morbilliform rash Serum sickness Urticaria
Other late reactions	Hemolytic anemia Interstitial nephritis Neutropenia Pulmonary infiltration Stevens-Johnson syndrome Thrombocytopenia Vasculitis

Cephalosporins with Side Chains that are Similar to Penicillins

Cephalothin Cefoxitin Cephaloridine	Side chains similar to Penicillin
Cefaclor Cefadroxil Cefprozil Cephalexin Cephatrizine Cephradine	Side chains similar to amoxicillin, ampicillin

*Pichichero ME. A review of evidence supporting the American Academy of Pediatrics recommendation for prescribing cephalosporin antibiotics for penicillin-allergic patients. Pediatrics 2005;115:1048

**Petz LD. Immunologic cross reactions between penicillins and cephalosporins: a review. J Infect Dis 1978(suppl):S74. Roland S et al . Drug Allergy: An Updated Practice Parameter. These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma. and Immunology, and the Joint Council of Allergy, Asthma and Immunology. Ann Allergy Asthma and Immunology 2010;105:259-273

1. Cephalosporin Cross-Reactivity With Other Beta Lactam Antibiotics

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