Animal and human bites

Also called Dog bite, Cat bite, Clenched fist injury

Cat bites and punches to the mouth infect far more often than they look like they should. Rabies is the question after any bite abroad.

What it is

Bites from animals or people, which are contaminated wounds with a high infection rate.

**Cat bites are deceptive.** Small puncture wounds inject bacteria deep into tissue and then seal over, and a large proportion become infected, often within 24 hours, particularly on the hand where infection tracks into tendon sheaths. They almost always need antibiotics.

Dog bites cause more crushing and tearing damage and infect less often, but severe bites to the face and in children can be devastating.

**Human bites are the most dangerous of all in one specific form**: the clenched fist injury, where a punch to the mouth cuts the knuckle on a tooth. It is often not described as a bite, and the wound looks trivial, and it seeds joint and tendon infection that can destroy the hand. Any knuckle wound after a punch needs urgent assessment and antibiotics.

High-risk wounds needing antibiotics are: all cat bites, all human bites, bites to the hand, face, feet or genitals, deep puncture wounds, bites over a joint or a prosthesis, and bites in anybody immunosuppressed, diabetic or without a spleen.

**Rabies** is the question after any mammal bite, scratch or lick on broken skin abroad, and it is invariably fatal once symptoms start. Post-exposure treatment works and must be started as soon as possible; wash the wound immediately with soap and water for 15 minutes and seek urgent advice.

Tetanus status must be checked for any bite.

Signs you might notice

A puncture, tear or crush wound.

Pain, swelling and redness.

Infection developing within 24 to 48 hours: increasing pain, spreading redness, heat, pus, swollen glands and fever.

Reduced movement of a finger, or pain on moving it, after a hand bite, which suggests tendon sheath infection and is a surgical emergency.

**Urgent, same day:** any cat bite; any human bite; any bite to the hand, face or genitals; a knuckle wound after a punch; a deep puncture; a bite in an immunosuppressed or diabetic person.

**Immediately:** severe bleeding, a bite to the face or neck of a child, or a bite abroad from any mammal, including bats in the UK.

999: heavy bleeding, extensive injury, or signs of sepsis.

How it can affect day-to-day life

Immediate wound care makes a real difference and is often skipped: running water and soap for several minutes, encouraging bleeding gently rather than stopping it immediately, and not closing the wound with plasters that seal in bacteria.

Bites to the hand are the ones that cause lasting disability, and the injuries most often underestimated are cat bites and knuckle wounds, precisely because they look minor.

Human bites in care settings, from people with dementia or a learning disability during personal care, are common and frequently unreported. They carry the same infection risk and need the same treatment, plus consideration of blood-borne virus risk, and they should be recorded and reviewed to understand the distress that caused them.

Blood-borne virus assessment after a human bite is appropriate where the skin is broken and the biter's status is unknown.

Bat bites and scratches in the UK carry a small rabies risk and need the same urgent assessment as bites abroad.

Dog bites in children are usually from a familiar dog in the home, and prevention is about supervision rather than about stray animals.

Supporting someone well

Wash immediately with running water and soap for several minutes; do not scrub.

Do not close or seal the wound; cover loosely with a clean dressing.

Get all cat bites, all human bites, and all hand, face and genital bites seen the same day.

Treat a knuckle wound after a punch as urgent, and say how it happened.

Ask about tetanus cover and about antibiotics.

**For any mammal bite abroad, or a bat in the UK, seek urgent advice about rabies.** Do not wait to get home.

Report and record bites in care settings, and review what caused the distress.

Ask about blood-borne virus assessment after a human bite.

Get any wound that becomes more painful, red or swollen reassessed urgently.

Where to get help

A GP practice, urgent treatment centre or minor injuries unit the same day.

A and E for hand bites with reduced movement, facial bites, heavy bleeding, or signs of sepsis.

Urgent advice about rabies after any bite abroad; the UKHSA rabies service advises clinicians.

UK Sepsis Trust for the warning signs of spreading infection.