Take biopsies from the following sites: If pemphigus or bullous pemphigoid is suspected and fresh lesions are present, take a 3 mm biopsy at the edge of the bulla. If only old lesions are available, biopsy adjacent area. If dermatitis herpetiformis is suspected, biopsy lesion and uninvolved area around lesions. If systemic lupus erythematosus is suspected, biopsy sun-exposed normal skin, preferably the wrist or deltoid area.
3 mm skin punch biopsy or mucous membrane biopsy
Formalin-fixed tissue, improper or discrepant labeling.
Specimen submitted fresh or in saline-moistened gauze should be placed into the vial with isopentane after the isopentane has been precooled in liquid nitrogen. The vial with the specimens should then be immersed in the liquid nitrogen and transported immediately.