(BMJ)—A 51-yo man presented w/ a painful rash on his L thigh, along w/ fever, paresthesias, vomiting, and diarrhea. Exam: vital signs WNL, well-appearing; 8x8 cm violaceous, tender area on L thigh w/ vesicles; smaller lesion on R thigh. U/S showed fascial fluid planes; CT demonstrated fat stranding in subcutaneous tissues. What is the dx?
Tinea cruris
Cellulitis
Herpes zoster
Bullous pemphigoid
Necrotizing fasciitis
You are correct. Necrotizing fasciitis may be suggested by exam findings such as skip lesions, crepitus, hemorrhagic bullae, or pain out of proportion to exam. CT is the imaging test of choice and may show fluid in the fascial planes, fascial thickening, subcutaneous emphysema, and fat stranding. Prompt dx of necrotizing fasciitis may be obfuscated by early presentation or distracting findings. A high clinical suspicion is necessary. Tx is emergent surgical debridement and broad-spectrum abx. This pt was given abx and taken immediately to the OR for debridement. The U/S findings helped expedite his tx.

Emerg Med J 2017;34:686-691.