Necrotising fasciitis with septic shock — FFICM MCQ

Correct answer: B — Urgent surgical exploration and debridement

The correct answer is B, urgent surgical exploration and debridement. This man has classic features of necrotising fasciitis: pain and skin tenderness extending well beyond the visible erythema, dusky/necrotic patches, rapid spread, and septic shock with a markedly raised lactate in a diabetic (a recognised risk factor). Necrotising fasciitis is a surgical emergency; the fascial necrosis cannot be reliably excluded or confirmed clinically, and mortality rises sharply with every hour of delay to operative source control. Surgical exploration is both diagnostic (confirming non-viable, easily separating fascia) and therapeutic (excision of all necrotic tissue), and must proceed in parallel with resuscitation and antibiotics, not after further tests. Why the other options are wrong: E. Wait for MRI to confirm fascial involvement: imaging is too slow and not required when clinical signs (pain beyond erythema, dusky skin, systemic toxicity) already meet the threshold for emergency surgery; delaying for MRI increases mortality. C. Start oral clindamycin and observe: oral antibiotics do not achieve adequate tissue penetration in a shocked, hypoperfused patient and antibiotics alone cannot debride dead, ischaemic fascia which perpetuates the septic focus. D. Apply compression and elevate the limb: this is management for venous or lymphatic oedema, not a necrotising infection, and does nothing to remove the necrotic source driving sepsis. A. Perform needle aspiration before escalation: aspiration is unreliable for diagnosis and provides no debridement of infected fascia, so it delays definitive treatment without benefit. Key point: In suspected necrotising fasciitis, clinical diagnosis mandates immediate surgical exploration and debridement alongside resuscitation and antibiotics, never delayed for imaging or microbiological confirmation.

Reference: RCEMLearning, Necrotising Fasciitis, UK Royal College of Emergency Medicine (rcemlearning.co.uk/reference/necrotising-fasciitis/)