๐ Case 1, Type I Polymicrobial Necrotizing Fasciitis
Patient: 62M with T2DM, presents with rapidly expanding erythema and exquisite pain on left lower leg after minor skin break. Temp 39.8ยฐC, HR 128, BP 88/52. WBC 24K, lactate 5.4, Cr 2.8. Skin: dusky discoloration, hemorrhagic bullae, crepitus on palpation.
Key findings: Crepitus = subcutaneous gas (Clostridium or mixed anaerobes). Pain out of proportion to exam appearance. Hemodynamic instability. LRINEC score > 6 (high risk). Type I = polymicrobial (diabetics, immunocompromised).
Management:
- Emergent surgical debridement, this is the ONLY definitive treatment. Do NOT delay for imaging
- Vancomycin + piperacillin-tazobactam + clindamycin (triple therapy: MRSA + GNR/anaerobes + toxin suppression)
- Aggressive IVF resuscitation, vasopressors for septic shock, ICU admission
- Plan for re-look debridement in 24-48h (often need multiple OR trips, "second look")
- Wound VAC after debridement stabilizes; delayed closure or skin grafting
Teaching point: "When in doubt, cut it out." The mortality of necrotizing fasciitis doubles with every hour of surgical delay. CT and MRI can miss early disease, if clinical suspicion is high, the patient goes to the OR, not radiology.
๐ Case 2, Type II (Group A Strep) Necrotizing Fasciitis
Patient: 35F previously healthy. Severe left arm pain after minor cut while gardening 48h ago. Now with rapidly spreading purple discoloration, bullae. Temp 40.1ยฐC, HR 135, BP 78/42. WBC 2.8K (leukopenia), platelets 68K. Blood cultures: GPC in chains.
Key findings: Type II = monomicrobial GAS (Streptococcus pyogenes). Can occur in healthy young adults. Streptococcal toxic shock syndrome (STSS): hypotension + organ failure + soft tissue infection. Leukopenia paradoxically indicates severe disease.
Management:
- Emergent radical surgical debridement, may require amputation if limb-threatening
- Penicillin G 4 million units IV q4h + clindamycin 900 mg IV q8h (clindamycin stops exotoxin production)
- IVIG 1-2 g/kg ร 1 dose (neutralizes streptococcal superantigens in STSS)
- ICU: vasopressors, ventilator support, blood products for DIC
- Notify public health, GAS necrotizing fasciitis is reportable in many jurisdictions
Teaching point: GAS necrotizing fasciitis can kill a healthy young adult in 24-48h. The clue is "pain out of proportion" + rapid systemic deterioration. IVIG is specifically beneficial for streptococcal toxic shock, it binds superantigens that drive the immune storm.
๐ Case 3, Fournier Gangrene
Patient: 58M with poorly controlled T2DM (A1c 11), presents with severe perineal pain, scrotal swelling, and foul-smelling discharge ร 2 days. Temp 39.4ยฐC, HR 130. Exam: scrotal erythema extending to perineum with crepitus. WBC 28K, lactate 4.8.
Key findings: Fournier gangrene = necrotizing fasciitis of the perineum/genitalia. Same pathophysiology as extremity necrotizing fasciitis. Diabetes is the #1 risk factor. Mortality 20-40% even with aggressive treatment.
Management:
- Emergent surgical debridement of all necrotic tissue (urology + general surgery)
- Same antibiotic regimen: vancomycin + piperacillin-tazobactam + clindamycin
- Fecal diversion (colostomy) if perineal wound is extensive (prevents fecal contamination)
- Suprapubic catheter if urethral involvement
- Daily wound care, re-look in 24-48h, wound VAC once clean, delayed reconstruction
Teaching point: Fournier gangrene follows the same treatment principles as all necrotizing fasciitis: emergent surgical debridement is the ONLY life-saving intervention. Antibiotics without surgery = death. The threshold for surgical exploration should be very low.