Necrotizing fasciitis

Necrotizing fasciitis is a progressive, rapidly spreading, inflammatory infection located in the deep fascia, with secondary necrosis of the subcutaneous tissues (see the images below). Because of the presence of gas-forming organisms, subcutaneous air is classically described in necrotizing fasciitis. This may be seen only on radiographs or not at all. The speed of spread is directly proportional to the thickness of the subcutaneous layer. Necrotizing fasciitis moves along the deep fascial plane.
Left upper extremity shows necrotizing fasciitis in an individual who used illicit drugs. Cultures grew Streptococcus milleri and anaerobes (Prevotella species). Patient would grease, or lick, the needle before injection. Necrotizing fasciitis at a possible site of insulin injection in the left upper part of the thigh in a 50-year-old obese woman with diabetes.
This condition has also been referred to as hemolytic streptococcal gangrene, Meleney ulcer, acute dermal gangrene, hospital gangrene, suppurative fascitis, and synergistic necrotizing cellulitis. Fournier gangrene is a form of necrotizing fasciitis that is localized to the scrotum and perineal area.
These infections can be difficult to recognize in their early stages, but they rapidly progress and require prompt recognition and aggressive treatment to combat the associated high morbidity and mortality.^[1] The causative bacteria may be aerobic, anaerobic, or mixed flora, and the expected clinical course varies from patient to patient.