Management of ß-Lactam Allergy:
1. Avoid unnecessary antimicrobial use, especially in the setting of viral infections.
2. Complete a thorough allergy assessment. Document:
Specific β-lactam received and route of administration – allergy more likely after parenteral exposure compared to oral
Date of reaction(s) – 80% of penicillin allergic patients lose sensitivity to penicillin after 10 years
Timing of reaction onset post β-lactam administration - IgE-mediated reactions usually occur immediately or within one hour
Description of reaction (e.g. throat swelling, trouble breathing, drug fever, Stevens-Johnson syndrome, vs. GI upset, rash [distinguish from hives]) and management (e.g. need for hospitalization)
Concurrent medications at the time of reaction
Exposure to any β-lactams since reaction
3. If patient has a reaction to a β-lactam that is not IgE-mediated and not severe (see #6 below), it is safe to administer other β-lactams.
4. If patient has a true IgE reaction to a penicillin with 1 or more of respiratory difficulty, hypotension, or hives:
avoid that penicillin and other penicillins (cross reactivity between penicillins is related to their β-lactam ring structure +/- side chains; see comprehensive ß-lactam cross-reactivity chart).
avoid cephalosporins with similar side chains (see comprehensive ß-lactam cross-reactivity chart).
can use cefazolin, or other cephalosporin with a dissimilar side chain (see comprehensive ß-lactam cross-reactivity chart), or carbapenem, as appropriate for the infection
before administering a β-lactam, counsel the patient on the risk versus benefit of the proposed β-lactam, including discussion of the risks of administration (which are much lower than usually assumed) and the benefits (e.g., use of first line antibiotic that is less likely to cause other adverse effects).
5. If patient has a true IgE reaction to a cephalosporin with 1 or more of respiratory difficulty, hypotension, or hives:
avoid that cephalosporin
avoid penicillins and other cephalosporins with similar side chains (see comprehensive ß-lactam cross-reactivity chart).
can use cefazolin, or penicillins or cephalosporins with a dissimilar side chain (see comprehensive ß-lactam cross-reactivity chart), or carbapenem, as appropriate for the infection.
before administering a β-lactam, counsel the patient on the risk versus benefit of the proposed β-lactam, including discussion of the risks of administration (which are much lower than usually assumed) and the benefits (e.g., use of first line antibiotic that is less likely to cause other adverse effects).
6. Avoid all β-lactams (penicillins, cephalosporins, carbapenems) in patients with a documented severe non-lgE-mediated reaction to penicillin: interstitial nephritis, hepatitis, hemolytic anemia, serum sickness, severe cutaneous reactions [e.g. Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia & systemic symptoms (DRESS)], including their use for graded challenge, desensitization, or skin testing. Use a non-β-lactam antibiotic.
7. Update the patient’s allergy history in the medical record and with the patient after doing the allergy assessment, including documentation of what was successfully administered.