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Three Part Question

In [adult patients with animal bites] does [wound closure] increase the [risk of infection]?

Clinical Scenario

A patient presents to the emergency department having been attacked by a dog. He has sustained lacerations to his hand and face. You provide oral analgesia, ensure he is covered for tetanus and thoroughly clean and irrigate the wounds under local anaesthesia. The patient asks you to close the wounds and you wonder if there is any evidence that this would increase the rate of infection.

Search Strategy

Medline 1966-05/04 using the OVID interface.
[exp "bites and stings" OR bite.mp] AND [suture.mp OR exp sutures OR steristrip.mp OR exp adhesives OR glue.mp] LIMIT to human AND English language.

Search Outcome

Altogether 74 papers were found of which 1 provided the best evidence to answer the clinical question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Maimaris C & Quinton DN, 1988, UK	96 ED patients with 169 dog bite lacerations (punctures excluded) randomised to primary closure or leaving wound open No antibiotics	PRCT	Infection	7 infections in sutured group (7.6%), versus 6 in open group (7.7%). (Not significant). Significantly more infections in hand wounds in both groups than elsewhere. (p<0.01). 5/30 infections of hand wounds sutured (16%), 4/45 infections of hand wounds left open (8%)	Randomisation method not stated Uncertainty about the adherence to standard wound toilet in early stages of study
			Cosmesis	Cosmesis good or fair in both groups (scar width 2-6mm in open versus 1-5 mm in closed)

Comment(s)

Only one PRCT has been performed to directly address infection rates in animal bite wounds treated by primary closure versus non-closure. No antibiotics were used in this study. It excludes puncture wounds, wounds infected at presentation, wounds with other structures involved, and those requiring plastic surgery. The study concludes that there is no significant difference in infection rates between the two groups except in those wounds occurring to the hands. Significantly more hand wounds became infected than wounds elsewhere, and of all hand wounds significantly more became infected in the group treated by closure. The study also noted that a delay to presentation of more than 10 hours was associated with an increased risk of infection but the relevant raw data is not presented.

Clinical Bottom Line

Bite wounds to the hand should be left open. Non-puncture wounds elsewhere may be safely treated by primary closure after thorough cleaning.

References

1. Maimaris C, Quinton DN. Dog-bite lacerations: a controlled trial of primary wound closure. Arch Emerg Med 1988;5(3):156-61.