Friday, October 3, 2008

Necrotising Fasciitis



Necrotising Fasciitis is a rapidly progressing soft tissue infection of the underlying fascia and fat. Organisms involved are either Group A beta-hemolytic streptococcus (Streptococcus pyogenes), or polymicrobial infections. The polymicrobial variety is more commonly found in patients with diabetes or in the post operative period. It is crucial to recognise these infections early as there is rapid tissue destruction. Severe pain, rapidly progressing erythema, and hemorrhagic bullae may be seen. About 10% of cases have crepitus. Patients commonly have fever, hypotension, and tachycardia and appear septic - sometimes out of proportion to their skin findings. CT and MRI are both very helpful visualizing gas along the fascial planes...however it is likely way easier to get a CT scan expeditiously.

Treatment revolves around a few principles. Most importantly, our surgical colleagues should get involved as early as possible as infected tissue must be debrided. Antibiotics should include a Beta-lactam with a beta-lactamase-inhibitor and Clindamycin. If a polymicrobial infection is suspected, it would be prudent to add metronidazole and better gram negative coverage.Clindamycin is kind of neat as it may be helpful not only by killing bacteria, but also by turning off the toxin-producing machinery of these bacteria. Interestingly, Intravenous Immunoglubulin therapy may be useful in necrotising fasciitis secondary to S. pyogenes infection.

Here is a great article guiding the reader how to approach a case:

Here is an article from Toronto looking at the evidence for IVIG: http://www.journals.uchicago.edu/doi/pdf/10.1086/515199

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