The information below is based on NICE NG184 Human and animal bites: antimicrobial prescribing.

For people with a human or animal bite:

• assess the type and severity of the bite, including what animal caused the bite, the site and depth of the wound, and whether it is infected
• assess the risk of tetanus, rabies, or a bloodborne viral infection and take appropriate action
• manage the wound with irrigation and debridement as necessary
• be aware of potential safeguarding issues in vulnerable adults and children.

Seek specialist advice for bites from a wild, exotic, or domestic animal (including farm animals) you are unfamiliar with.

Take a swab for microbiological testing to guide treatment if there is discharge (purulent or non-purulent) from the bite wound.

Treatment and prophylaxis

Offer an antibiotic if there are signs and symptoms of infection, such as increased pain, inflammation, fever, discharge, or an unpleasant smell.

If patient presents > 72 hours after the bite, assess for signs and symptoms of infection and offer antibiotic treatment if present. If there are no signs or symptoms of infection present, do not offer antibiotic prophylaxis for late presentation.

If the patient is pregnant, seek specialist advice.

Human bites

Do not offer antibiotic prophylaxis to people with a bite that has not broken the skin.

Do offer antibiotic prophylaxis to people with a bite that has broken the skin and drawn blood.

Consider antibiotic prophylaxis for people with a bite that has broken the skin but not drawn blood if it:

• involves a high-risk area such as the hands, feet, face, genitals, skin overlying cartilaginous structures, or an area of poor circulation or
• is in a person at risk of a serious wound infection because of a comorbidity (such as diabetes, immunosuppression, asplenia, or decompensated liver disease).

Cat bites

Do not offer antibiotic prophylaxis to people with a bite that has not broken the skin.

Do offer antibiotic prophylaxis to people with a bite that has broken the skin and drawn blood.

Consider antibiotic prophylaxis for people with a bite that has broken the skin but not drawn blood if:

• the wound could be deep or
• involves a high-risk area such as the hands, feet, face, genitals, skin overlying cartilaginous structures, or an area of poor circulation or
• is in a person at risk of a serious wound infection because of a comorbidity (such as diabetes, immunosuppression, asplenia, or decompensated liver disease).

Bites from a dog or other traditional pet (excluding cat bites)

Do not offer antibiotic prophylaxis to people with a bite that has not broken the skin or has broken the skin but not drawn blood.

Do offer antibiotic prophylaxis to people with a bite that has broken the skin and drawn blood if it:

• has penetrated bone, joint, tendon, or vascular structures or
• is deep, is a puncture or crush wound, or has caused significant tissue damage or
• is visibly contaminated (for example, if there is dirt or a tooth in the wound).

Consider antibiotic prophylaxis for people with a bite that has broken the skin and drawn blood if it:

• involves a high-risk area such as the hands, feet, face, genitals, skin overlying cartilaginous structures, or an area of poor circulation or
• is in a person at risk of a serious wound infection because of a comorbidity (such as diabetes, immunosuppression, asplenia, or decompensated liver disease).

Antibiotics for prophylaxis and treatment

Treatment duration:

• Prophylaxis = 3-day course
• Treatment = 5-day course

Reassess the bite if:

• symptoms or signs of infection develop or worsen rapidly or significantly at any time, or do not start to improve within 24 to 48 hours of starting treatment or
• the person becomes systemically unwell or
• the person has severe pain that is out of proportion to the infection.

If a swab has been sent to microbiological testing:

• review the choice of antibiotic(s) when results are available and
• change the antibiotic(s) according to the results as appropriate.

Co-amoxiclav

• Adults and children over 12 years of age:
  • 500mg/125mg three times a day
• Children 1 month to 11 years of age (doses given three times a day):
  • 1 month to 11 months: 0.25ml/kg (125mg/31mg/5ml suspension)
  • 1 year to 5 years: 0.25ml/kg or 5ml (125mg/31mg/5ml suspension)
  • 6 years to 11 years: 0.15ml/kg or 5ml (250mg/62mg/5ml suspension)
• See section 5.1.1 Penicillins

Penicillin allergy (aged 12 years and above)

Doxycycline

• 100mg twice a day

PLUS

Metronidazole

• 400mg three times a day

See sections 5.1.3 Tetracyclines and 5.1.11 Metronidazole and tinidazole

Penicillin allergy (aged under 12 years)

Co-trimoxazole (off-label)

• Children 6 weeks to 11 years of age (doses given twice a day):
  • 6 weeks to 5 months: 120mg or 24mg/kg
  • 6 months to 5 years: 240mg or 24mg/kg
  • 6 years to 11 years: 480mg or 24mg/kg
• See section 5.1.8 Sulfonamides and trimethoprim

Pregnancy

Seek specialist advice.

Referral

Refer people to hospital if they have:

• symptoms or signs suggesting a more serious illness or condition (these include severe cellulitis, abscess, osteomyelitis, septic arthritis, necrotising fasciitis or sepsis) or
• a penetrating wound involving arteries, joints, nerves, muscles, tendons, bones or the central nervous system.

Consider referral or seek specialist advice if:

• the bite(s) is from a wild, exotic, or domestic animal (including farm animals) you are unfamiliar with or
• they are systemically unwell or
• they have developed symptoms or signs of infection after taking prophylactic antibiotics or
• they have lymphangitis (may represent infection caused by Pasteurella species – avoid empirical treatment with flucloxacillin or erythromycin) or
• they are at risk of a serious wound infection because of a pre-existing medical condition or
• they cannot take oral antibiotics (in which case, explore with the specialist whether locally available options for parenteral antibiotics at home or in the community, rather than in hospital, are appropriate) or
• the bite is infected and is not responding to oral antibiotics or
• the bite is in an area of poor circulation.