Subcutaneous emphysema or necrotizing fasciitis after insect bite?

The rapid form of subcutaneous emphysema after an insect bite is hard to distinguish from necrotizing fasciitis.

Here we report a case of benign subcutaneous emphysema after an insect bite on the hand of an 18-year-old Caucasian man. The puncture area in the first web space of his hand was erythematous and swollen. After 4 h, he began to hear crackling sounds in the hand. Although conservative management was provided, he experienced gradually increasing pain and rapid progression in swelling and crepitation. The symptoms regressed after fasciotomy.

This is the fourth reported case of benign subcutaneous emphysema after an insect bite in the literature. Although benign emphysema has a good prognosis after treatment, it is similar to necrotizing fasciitis. Proper diagnosis can only be established with histological and microbiological investigations, but in cases where early histological and microbiological investigations cannot be performed, biochemistry and radiological test should be used.