Test | Specimen | Site | Procedure | Transport |
Histopathology (H&E) | Skin or mucous membrane | Lesional or part lesional | At least 4 mm punch biopsy* - Specimen should contain intact epidermis/epithelium, basement membrane zone, and upper dermis/subepithelium
- Avoid torsion and crushing to prevent separation artifact
| In formalin to a dermatopathology laboratory |
DIF | Skin or mucous membrane | Perilesional - For cutaneous lesions, an erythematous or urticarial area next to a blister from a proximal anatomical location is ideal
- For mucous membrane lesions, avoid areas of scarring; normal-appearing epithelium since perilesional tissue may be friable
| At least 4 mm punch biopsy* - Specimen should contain intact epidermis/epithelium, basement membrane zone, and upper dermis/subepithelium
- Avoid torsion and crushing to prevent separation artifact
| In Michel's or Zeus medium to an immunodermatology laboratory¶ |
IIF and ELISA | Serum | Peripheral blood | Serum separated from at least 5 mL of blood obtained by venipuncture (red top, no anticoagulant); send serum separated from clotΔ | In serum tube to an immunodermatology laboratory |