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High-risk tetanus-prone plantar puncture wound — MSRA MCQ

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HardAnkle and FootHigh-risk tetanus-prone plantar puncture woundMSRA

A 29-year-old landscape gardener attends an urgent treatment centre 30 hours after stepping on a rusty nail that penetrated the sole of his boot and punctured the plantar aspect of his foot. The nail and wound were heavily contaminated with garden soil. The wound has been thoroughly irrigated and explored; plain radiographs show no retained foreign body or fracture. He is systemically well and has no clinical evidence of infection. His vaccination record confirms a three-dose tetanus primary course completed at age 12 years, but no subsequent tetanus-containing vaccine. He is not immunosuppressed and has no history of vaccine anaphylaxis. What is the most appropriate tetanus post-exposure prophylaxis today?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — One immediate dose of Td/IPV vaccine plus 500 IU human tetanus immunoglobulin at a different site

Explanation lettering: D = shown as A · E = shown as B · B = shown as D · A = shown as E

This is a high-risk tetanus-prone wound: it is a puncture injury acquired in a contaminated environment, with heavy soil contamination. He has received an adequate priming course for wound risk assessment (at least three doses), but his last tetanus dose was more than 10 years ago. He should therefore receive an immediate reinforcing dose of tetanus-containing vaccine. Because the injury is high risk, human tetanus immunoglobulin (TIG) is also indicated. The TIG dose is 500 IU because more than 24 hours have elapsed since injury; heavy contamination is an additional indication for this dose. Vaccine and TIG should be administered at separate sites. Td/IPV is the appropriate tetanus-containing vaccine in this adult. A is appropriate after adequate priming when the last dose was within 10 years. B would be appropriate for a tetanus-prone but non-high-risk wound when a primed individual is overdue a booster. C omits active immunisation and would not provide appropriate long-term protection. D uses an insufficient TIG dose for delayed presentation and heavy contamination.

Reference: Tetanus: the green book, chapter 30 (Updated 2 June 2025) — https://assets.publishing.service.gov.uk/media/683dceaa81deb72cce2680fc/Tetanus-green_book-chapter-30-02-06-25.pdf Tetanus: the green book, chapter 30 (Updated 2 June 2025) — https://assets.publishing.service.gov.uk/media/683dceaa81deb72cce2680fc/Tetanus-green_book-chapter-30-02-06-25.pdf Tetanus: the green book, chapter 30 (Updated 2 June 2025) — https://assets.publishing.service.gov.uk/media/683dceaa81deb72cce2680fc/Tetanus-green_book-chapter-30-02-06-25.pdf