Derm Cases · Dermatology / Emergency Medicine / Surgery
OSCE — pain out of proportion: suspected necrotising fasciitis emergency pathway
An 8-minute OSCE station on early recognition of necrotising soft-tissue infection, limits of LRINEC, immediate source-control pathway, and adjunctive clindamycin with broad empiric antibiotics.
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Study tools
Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE station on early recognition of necrotising soft-tissue infection, limits of LRINEC, immediate source-control pathway, and adjunctive clindamycin with broad empiric antibiotics.
Brief (to candidate)
A 55-year-old man with diabetes presents with 18 hours of severe left leg pain after a minor abrasion. The limb is erythematous and tense; pain seems far worse than the visible skin change. He is tachycardic and febrile. You have 8 minutes to recognise the emergency, risk-stratify, and start definitive management.
Candidate instructions
- Recognise red-flag signs of necrotising fasciitis / NSTI.
- State the role and limits of LRINEC.
- Outline immediate resuscitation and empiric antibiotics including toxin-suppression.
- Call for urgent surgical exploration without waiting for imaging confirmation.
- Mention Fournier gangrene and other special sites.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Recognition | Pain out of proportion, rapid spread, tense oedema, systemic toxicity; later crepitus/bullae/skin necrosis — early skin may look deceptively mild[1][4][5] |
| Red flags | Diabetes/immunosuppression/trauma/IV drug use; woody hardness; anaesthesia of skin; haemorrhagic bullae; multi-organ dysfunction |
| LRINEC | Can support suspicion (e.g. score ≥6 high risk) but never rules out NF; do not delay surgery for labs/score alone[6][7] |
| Resuscitation | ABC, IV access, fluids, bloods (FBC, CRP, lactate, cultures), early senior/surgical escalation |
| Antibiotics | Broad empiric cover for polymicrobial ± GAS/MRSA per local protocol; add clindamycin for toxin suppression in streptococcal/clostridial disease when indicated; do not substitute for surgery[1][2] |
| Source control | Emergent surgical exploration and debridement is definitive; imaging only if it will not delay theatre in equivocal stable cases |
| Communication | Explains life/limb threat; serial re-looks often needed; documents time-critical plan |
Model key actions
- Suspect NF from pain out of proportion + systemic toxicity even with modest early erythema.[5]
- Resuscitate, give broad antibiotics ± clindamycin, and call surgery immediately — do not wait for perfect imaging/LRINEC.[1][2][6]
- Plan for repeat debridement and ICU-level care.
Common errors
- Treating as simple cellulitis with oral antibiotics and delayed review.
- Using LRINEC to rule out disease.
- Delaying theatre for CT/MRI in an unstable patient.
- Omitting clindamycin / toxin-suppression when GAS NF is likely.
- Missing perineal (Fournier) source in febrile patients with scrotal/perineal pain.
References6ShowHide
- [1]Stevens DL, Bryant AE, Goldstein EJ. Necrotizing Soft Tissue Infections. Infectious disease clinics of North America, 2021.PMID 33303335
- [2]Babiker A, Li X, Lai YL, et al. Effectiveness of adjunctive clindamycin in β-lactam antibiotic-treated patients with invasive β-haemolytic streptococcal infections. The Lancet Infectious Diseases, 2021.PMID 33333013
- [4]Hasham S, Matteucci P, Stanley PR, et al. Necrotising fasciitis. BMJ, 2005.PMID 15817551
- [5]Goh T, Goh LG, Ang CH, et al. Early diagnosis of necrotizing fasciitis. The British journal of surgery, 2014.PMID 24338771
- [6]Bechar J, Sepehripour S, Hardwicke J, et al. Laboratory risk indicator for necrotising fasciitis (LRINEC) score: a systematic review. Annals of the Royal College of Surgeons of England, 2017.PMID 28462647
- [7]Fernando SM, Tran A, Cheng W, et al. Necrotizing Soft Tissue Infection: Diagnostic Accuracy of Physical Examination, Imaging, and LRINEC Score. Annals of surgery, 2019.PMID 29672405