Cephalosporins allergy allergic patients

Primary cephalosporin allergy in patients not allergic to peniciUin has been reported, but the exact frequency is... 

Verify the patient s allergy history and the type of reaction experienced. Attempt to discern between true allergy and adverse event. (3-Lactam-allergic patients may receive clindamycin, vancomycin, or other antimicrobials. Crossreactivity between penicillin allergy and cephalosporins is low but cephalosporins should be avoided in patients with a history of anaphylaxis to penicillins. 

Neither in vitro tests nor skin tests reliably predict cephalosporin allergy (166). The true frequency of allergic reactions in penicillin-allergic patients exposed to cephalosporins has been estimated to be 1 or 2% (167). Nevertheless, when there is a history of penicillin anaphylaxis or other severe IgE-mediated reactions, it is wise to avoid cephalosporins. 

Allergy Cephalosporins cause a range of allergic reactions from skin rashes to anaphylactic shock. These reactions occur less frequently with cephalosporins than with penicillins. Complete cross-hypersensitivity between different cephalosporins should be assumed. Cross-reactivity between penicillins and cephalosporins is incomplete (5-10%), so penicillin-allergic patients are sometimes treated successfully with a cephalosporin. However, patients with a history of anaphylaxis to penicillins should not be treated with a cephalosporin. 

Some types of allergic reaction, for example immediate or delayed-type skin allergies, serum-sickness-like reactions and anaphylactic reactions, may occur in a proportion of patients given penicillin treatment. There is some, but not complete, cross-allergy with cephalosporins. 

It has also been reported that patients with allergic-like events after penicillin treatment have had a markedly risk of events after subsequent cephalosporin antibiotics. Cross-reactivity is not an adequate explanation for this increased risk and the data obtained indicate that cephalosporins can be considered for patients with penicillin allergy <2006MI354.ell>. Comparisons of parenteral broad-spectrum cephalosporins have been tested against bacteria isolated from pediatric patients. The results have indicated that cefepime has been the most broad-spectrum cephalosporin analyzed and it is a very potent alternative for the treatment of contemporary pediatric infections in North America <2007MI109>. The historical safety of the most commonly used oral cephalosporins has been reviewed <2007MIS67>. The antimicrobial spectrum and in vitro potency of the most frequently prescribed orally administered cephalosporins (cefaclor, cefdinir, cefpodoxime, cefprozil, cefuroxime axetil and cephalexin has also been reviewed <2007MIS5>. 

Allergic manifestations The cephalosporins should be avoided or used with caution in individuals allergic to penicillins (about 5 to 15% show cross-sensitivity). In contrast, the incidence of allergic reactions to cephalosporins is 1-2% in patients without a history of allergy to penicillins. 

Note Penicillin and cephalosporins share a common beta-lactam structure. People who are allergic to penicillin are approximately 4 times more likely to develop an allergic reaction to a cephalosporin than those people who have no penicillin allergy. (From 5 to 16% of patients allergic to penicillin develop reactions to cephalosporins)... 

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