Mediated by IgE antibodies
Onset usually within 1 hour (up to 24h)
Cross-reactivity information useful
Skin Testing useful
Mediated by IgG or IgM antibodies
Onset usually >72 hours (up to 14 days)
Reaction is drug specific
Cross-reactivity information is not useful
Offending drug is contraindicated
Mediated by antigen-antibody complexes
Onset usually >72 hours (up to 14 days)
Cross-reactivity information is lacking
If severe (e.g. AIN), all beta-lactams are considered contraindicated unless guided by an expert
Mediated by T-cells
Onset usually >72 hours (up to 3-4 weeks)
Cross-sensitivity is possible but not predictable by skin testing or oral challenge
If severe (e.g. SJS), all beta-lactams are considered contraindicated unless guided by an expert