Necrotising fasciitis
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Web Resources for Necrotising fasciitis (search term=Necrotizing fasciitis)
ICD 10 code: M72.6
Relevant Clinical Literature
UK Guidance
Other Wikis
Medpedia on Necrotising fasciitis (Less technical, good quality control)
Wikipedia on Necrotising fasciitis (Less technical, ? quality control)
Necrotising fasciitis is a rare, but rapidly progressive and potentially life-threatening infection of the soft tissues. A successful outcome depends on a high index of suspicion, early recognition, aggressive debridement, intravenous antibiotics and supportive treatment for sepsis.
An underlying systemic condition is common, e.g.
- Malnutrition
- Excessive alcohol use
- Diabetes mellitus
- Immunosuppression, including undiagnosed AIDS
Contents |
Features
May present with pain, swelling and fever, but external manifestations of early disease can be unremarkable and is often mistaken for simple cellulitis. There may be a history of preceding breach of the skin.
Scores have been designed based on analysis of apparent predisposing factors.[1]
Pain out of proportion to the external appearence is a common feature (therefore be careful to dismiss pain in i.v. drug users). Fluid-filled bullae and crepitus due to subcutaneous gas strongly support the diagnosis, but are often late signs.
Systemic symptoms normally associated with severe sepsis can be absent in early disease, but as the tissue damage progresses, signs of septic shock may be apparent.
| Variable | Score |
|---|---|
| C-reactive protein | |
| <150 | 0 |
| ≥150 | 4 |
| Total white cell count (per mm3 | |
| <15 | 0 |
| 15-25 | 1 |
| >25 | 2 |
| Haemoglobin (g/dL) | |
| >13.5 | 0 |
| 11-13.5 | 1 |
| <11 | 2 |
| Sodium | |
| ≥135 | 0 |
| <135 | 2 |
| Creatinine | |
| ≤141 | 0 |
| >141 | 2 |
| Glucose | |
| ≤10 | 0 |
| >10 | 1 |
Pathology
Synergistic polymicrobial infection.[2] Group A Streptococcus is isolated from a number of cases and is thought to produce toxins than favour fascial invasion.
Bacterial toxins and enzymes allow invasion and undermining of the fascial layer. The perforating blood vessels that supply the overlying skin are invaded and thrombose, resulting in necrosis of the overlying skin.
Treatment
Resuscitation
Treat septic shock if present.
Surgery
Prompt and aggressive debridement. Soft tissue should be excised until bleeding tissue is reached. An conservative approach is counter-productive as unhealthy margins may continue to progress, requiring more extensive debridement at a later stage.
Serial assessment in the sterile confines of theatre are usually done in days following the index debridement to ensure debridement is adequate.
Antibiotics
Broad-spectrum antibiotics are usually administered as soon as possible after wound and blood cultures have been taken.
Antibiotics need to cover group A Streptococcus, anaerobes and Gram negative organisms. Several combinations are possible, e.g. meropenem and clindamycin. Clindamycin had good soft tissue penetration and may rapidly turn off Streptococcal toxin production.
Adjunctive Therapies
Intravenous immunoglobulin is often given for its immunomodulatory properties, although there is little evidence to support its use.
References
- ↑ Wong CH, Khin LW, Heng KS, Tan KC, Low CO. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections. Critical care medicine. 2004 Jul; 32(7):1535-41.
- ↑ Elliott D, Kufera JA, Myers RA. The microbiology of necrotizing soft tissue infections. American journal of surgery. 2000 May; 179(5):361-6.
