Infected clenched-fist human bite with suspected metacarpophalangeal joint involvement — MRCEM SBA MCQ

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HardInfection and sepsisInfected clenched-fist human bite with suspected metacarpophalangeal joint involvementMRCEM SBA

A 29-year-old man presents 36 hours after punching another person in the mouth. He has a 6 mm wound over the third metacarpophalangeal joint. The hand is swollen, and passive movement of that joint is markedly painful. His temperature is 38.4°C. He can extend the finger fully. A hand radiograph shows no fracture or retained tooth fragment. He can take oral medicines and has no antibiotic allergy. Which initial management plan is most appropriate?

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Correct answer: D — Give intravenous co-amoxiclav and arrange urgent hand-surgery exploration.

This is an infected clenched-fist human bite with likely joint involvement. A tooth can penetrate the metacarpophalangeal joint when the fist is clenched; once the hand opens, the small skin wound may no longer align with the deeper injury. Preserved extension and a radiograph without a tooth fragment do not resolve that concern. Fever and marked pain on passive joint movement make a superficial wound-management approach inappropriate. Urgent hand-surgery assessment for exploration and washout is required, alongside admission and intravenous bite-appropriate antibiotics. NICE lists intravenous co-amoxiclav as the first-choice intravenous treatment for a severely unwell adult with a human bite and recommends hospital referral for a penetrating joint wound or suspected septic arthritis. ([nice.org.uk](https://www.nice.org.uk/guidance/ng184/chapter/Recommendations)) A uses an appropriate agent but an inadequate initial route for this clinically significant deep infection; oral treatment suits a less severe bite without suspected joint infection. B covers common skin organisms but not the range of pathogens relevant to a human bite. C delays the surgical decision despite signs of joint infection; a 48-hour antibiotic review is not a substitute for urgent referral. E makes further imaging a prerequisite for referral, delaying assessment of a joint that may need washout. ([nice.org.uk](https://www.nice.org.uk/guidance/ng184/chapter/Recommendations))

Reference: Human and animal bites: antimicrobial prescribing — Recommendations (4 November 2020) — https://www.nice.org.uk/guidance/ng184/chapter/Recommendations Fight Bite Injury (Date not stated) — https://www.gloshospitals.nhs.uk/our-services/services-we-offer/trauma-orthopaedics/hand-clinic/hand-trauma/the-fight-bite-injury/