PEN-FAST penicillin allergy rule
Identifies low-risk penicillin allergy labels suitable for direct oral challenge.
Inputs
Reaction within the past 5 years
Anaphylaxis or angioedema, or severe cutaneous adverse reaction (SJS, TEN, DRESS)
Reaction required treatment
Worked calculation
Your values are highlighted.
- Points
When to use
- Patients reporting penicillin allergy.
Pearls and pitfalls
- Score below 3: very low risk; a direct oral amoxicillin challenge was noninferior to skin testing (PALACE trial).
Why use
Drives safe delabeling.
| Criterion | Points |
|---|---|
| Reaction within the past 5 years | +2 |
| Anaphylaxis or angioedema, or severe cutaneous adverse reaction (SJS, TEN, DRESS) | +2 |
| Reaction required treatment | +1 |
Any history of SJS, TEN, DRESS, or other severe delayed reaction excludes oral challenge.