Principles of Delayed Skin Testing
| Phenotype | Patch Testing | Delayed IDT | ELISpot | HLA Testing |
|---|---|---|---|---|
| MPE | ✓ | ✓ | — | — |
| FDE | ✓ (lesion site) | ✓ | — | — |
| AGEP | ✓ | ✓ | — | — |
| DRESS | ✓ | ✓ | ✓ (acute preferred) | ✓ (if known assoc.) |
| SJS/TEN | ✓ (low sensitivity) | ✕ Contraindicated | ✓ (acute preferred) | ✓ (if known assoc.) |
| Organ Injury (DILI) | — | — | — (limited data) | — (limited data) |
Important
No delayed skin testing method has 100% negative predictive value.
| Medication | Recommendation |
|---|---|
| Antihistamines | Okay to continue |
| Beta-blockers | Okay to continue |
| Systemic steroids | Off >= 1 month or prednisone equivalent <= 10 mg/day |
