Penicillin Allergy Assessment Algorithm

e.g., GI intolerance, Diarrhea, Headache

e.g., Morbilliform rashes (in absence of pruritus) are not typical of type I reactions

Poorly described symptoms (no hospitalization, no systemic involvement, occurred >10 yrs ago)

e.g., angioedema, urticarial/pruritus, laryngeal edema, wheezing, hypotension.

Poorly described symptoms but patient has poorly controlled and/or unstable cardiac or respiratory comorbidity.

Impacts all Penicillins:

• Stevens-Johnson syndrome

• Toxic epidermal necrolysis DRESS syndrome

• Immune hepatitis

• Interstitial nephritis Small vessel vasculitis

Drug-Specific:

• Hemolytic anemia

• Thrombocytopenia

• Agranulocytosis

• Neutropenia

Drug-induced hemolytic anemia, thrombocytopenia, agranulocytosis, and neutropenia are drug-specific. Cross-reactivity between cephalosporins and penicillins does not appear to occur. Avoid the offending drug.