Oozing puncture wound on foot
A minor foot injury did not prompt our patient to seek treatment. The painful swelling that came later, did.
Diagnosis is often made on clinical evaluation
The definitive diagnosis of necrotizing fasciitis is made by histological examination of the debrided specimen or deep skin tissue biopsy. Fascial necrosis with thrombosed blood vessels and a dense infiltrate of inflammatory cells is seen on histological evaluation.
However, diagnosis is often reached on clinical evaluation. Rapidly deteriorating local signs and symptoms together with systemic toxicity should prompt a working diagnosis of necrotizing fasciitis.
Laboratory tests (white blood cell count, blood urea nitrogen level, sodium levels, creatinine levels, erythrocyte sedimentation rates, C-reactive protein levels) and radiographic evaluation (X-rays, computed tomography [CT], and magnetic resonance imaging [MRI]) are useful adjuncts in reaching the diagnosis.
Prompt treatment is the name of the game
Antibiotic therapy is guided by gram stain and bacterial culture results. (When the clinical suspicion of necrotizing fasciitis is reached, empirical antibiotics should be started right away.) Broad-spectrum antibiotics covering gram positive, gram negative, and anaerobic bacteria should be used. The patient’s age, weight, and liver and renal function should also be considered before starting antibiotics.
Choices of antibiotics include penicillin for gram positive cover and an aminoglycoside or third-generation cephalosporin for gram negative counteraction. Metronidazole (Flagyl) may be considered for anaerobic superimposed infections. Adjunctive clindamycin is also recommended—especially in group A streptococcal infections—because it suppresses toxin production, inhibits M-protein synthesis, and facilitates phagocytosis.5 In addition, hyperbaric oxygen therapy and intravenous immunoglobulin are increasingly being utilized in the management of necrotizing fasciitis.6 Their efficacy has yet to be conclusively established.
Surgical debridement. The importance of prompt and thorough surgical debridement cannot be stressed enough. Large soft-tissue defects created by surgery can be treated with vacuum-assisted closure dressings, local or free soft-tissue flaps, and/or skin grafts. In extreme cases, limb amputation may be necessary.
