| 1. No evidence of an unexpected β-lactam hypersensitivity reaction |
| – Gastrointestinal reaction only (e.g., nausea, vomiting, diarrhea) |
| – Only nonspecific reaction (e.g., headache, rhinoconjunctivitis, palpitations), often associated with fear of drug hypersensitivity |
| – Urticaria with onset > 1 day after discontinuation of β-lactam or persisting for days after drug discontinuation |
| – Exanthem with onset > 1 week after discontinuation of β-lactam |
| – Only family history positive for drug hypersensitivity |
| 2. Indications of questionable reactions with low risk |
| – Urticaria occurring only after a delay (> 6 hours after ingestion) |
| – Non-remembered reaction > 10 years ago without therapy |
| – Mild rash in childhood, especially associated with infection |
| 3. Evidence of non-severe delayed-onset drug exanthema |
| – Maculopapular (uncomplicated) drug-induced exanthema with therapy < 10 years ago |
| 4. Indications of moderately severe immediate reactions |
| – Urticaria |
| – Angioedema |
| – Tachycardia |
| 5. Evidence of severe drug reactions with high risk |
| – Vomiting, diarrhea along with other anaphylaxis symptoms |
| – Wheezing / dyspnea |
| – Blood pressure drop |
| – Unconsciousness |
| – Anaphylaxis |
| – Cardiovascular and/or respiratory arrest |
| 6. Indications of possible severe β-lactam hypersensitivity reactions that cannot be treated with sufficient safety in case of recurrence and therefore usually leads to an elimination of β-lactams and administration of alternative antibiotics |
| – Drug reaction with eosinophilia and systemic symptoms (DRESS, drug hypersensitivity syndrome) |
| – Hemolytic anemia or cytopenia |
| – Acute nephritis or hepatitis |
| – Serum sickness |
| – Severe exanthema with blistering of the skin and/or mucosa (Stevens-Johnson syndrome, toxic epidermal necrolysis) |
