> type of [[Necrotising infections|necrotising fasciitis]] localised to perineum and genital areas - infection of subcut tissues and muscles with gas-forming organisms. - Uncommon in developed countries. - Poor vascular supply, contamination, poor socio-economic groups, diabetes, & IVDA have increased risk. **Causes:** - Clostridium perfringens & other spp - E.Coli - S.pyogenes - Bacteroides. **Presentation:** - History: Wound trauma, fever, pain, smell, out of proportion pain. - Exam: Fever, shocked. Tense skin around infection, initialy blanching followed by dusky red, haemorrhagic bullae, crepitus **Investigations:** - FBC, culture, swabs, x-ray (may see gas in tissue planes) **Management:**  - ==Meropenem== 1g (child: 25mg/kg) IV q8h PLUS EITHER ==clindamycin== 600mg (child: 15mg/kg) IV q8h OR lincomycin 600mg (child: 15mg/kg) IV q8h.  - pip-taz can be alternative to mero  - If S.pyogenes indicated replace meropenem with benzylpenicillin 1.8g (child 45mg/kg) IV q4h.  - likely ==vanc== 25-30mg/kg IV - Mixed clostridium antitoxins - Surgical debridement ± amputation - Hyperbaric Oxygen therapy