Trimethoprim-Sulfamethoxazole Allergy Decision Rule (SULF-FAST)
Identifies low-risk antimicrobial sulfonamide allergies.
Advice
Document the SULF-FAST score and any subsequent allergy testing/challenge outcomes in the medical record to support future clinical decisions.
Management
-
Score <3 (low risk): Consider TMP-SMX direct oral challenge with appropriate observation; follow local/institutional protocols.
-
Score ≥3: (elevated risk): Refer to allergy/immunology for a more detailed evaluation, which may include skin testing.
Critical Actions
Patients with a history of anaphylaxis or severe cutaneous reaction should not undergo direct oral challenge.