What is the recommended management for a human bite?

Management of Human Bites

Immediately irrigate the wound with copious sterile saline or water, administer amoxicillin-clavulanate as first-line antibiotic therapy for high-risk wounds, and never close infected wounds or most non-facial wounds primarily. 1

Immediate Wound Care

• Irrigate the wound immediately and thoroughly with sterile normal saline or water to remove debris and reduce bacterial load—this takes priority over antibiotic administration 1
• Avoid using iodine or antibiotic-containing solutions for routine cleansing, as these can damage tissue 1
• Remove only superficial debris; avoid aggressive debridement that may enlarge the wound 1
• Do not irrigate under high pressure, as this can drive bacteria deeper into tissue layers 2

Wound Closure Decisions

• Do not close infected wounds under any circumstances 1
• For clean, non-infected wounds presenting within 8 hours, approximate edges with Steri-Strips rather than sutures 1
• Facial wounds are the critical exception: these may be closed primarily after meticulous wound care, irrigation, and prophylactic antibiotics due to cosmetic concerns and excellent blood supply 1, 3
• All other wounds should heal by secondary intention or delayed primary closure 1

Antibiotic Therapy

Indications for Antibiotics

Administer antibiotics for 3-5 days for: 2

• Fresh, deep wounds
• Wounds on hands (the only location with evidence-based support for prophylaxis) 2
• Wounds on feet, near joints, face, or genitals 2
• Patients at elevated infection risk (immunocompromised, prosthetic valves/joints) 2
• Clenched-fist injuries (fight bites)—these are surgical emergencies 1, 4

Do not give antibiotics if: 2

• Patient presents ≥24 hours after the bite with no clinical signs of infection

First-Line Antibiotic Regimens

Oral therapy (first-line): 1

• Amoxicillin-clavulanate—provides coverage for Streptococcus (50% of human bites), S. aureus (40%), Eikenella corrodens (30%), and anaerobes 2, 1

Oral alternatives for penicillin allergy: 1

• Doxycycline alone
• Penicillin VK plus dicloxacillin
• Fluoroquinolone (ciprofloxacin, levofloxacin, or moxifloxacin) plus metronidazole or clindamycin for anaerobic coverage

Intravenous therapy (for severe infections): 1

• First-line: Ampicillin-sulbactam or piperacillin-tazobactam
• Alternatives: Cefoxitin (second-generation cephalosporin) or carbapenems (ertapenem, imipenem, meropenem)

Duration of Treatment

• Standard wound infections: 7-10 days 1
• Septic arthritis/synovitis: 3-4 weeks 1
• Osteomyelitis: 4-6 weeks 1

Tetanus Prophylaxis

• Administer tetanus toxoid 0.5 mL intramuscularly if vaccination status is outdated or unknown 1
• This is mandatory for all human bites 1

Infectious Disease Transmission Risk

• Consider post-exposure prophylaxis for hepatitis B, hepatitis C, and HIV based on the biter's known or suspected status 2
• Rabies transmission from human bites is extraordinarily rare in the United States and typically not a concern 1
• Consider rabies prophylaxis only in exceptional circumstances where the biting person has suspected rabies exposure or compatible clinical signs 1

Special Considerations: Clenched-Fist Injuries

These are the most dangerous human bites and require aggressive management: 1, 4

• Obtain immediate expert hand surgery evaluation for potential penetration into synovium, joint capsule, or bone 1
• High risk for septic arthritis and osteomyelitis 1
• Often require surgical exploration, debridement, and intravenous antibiotics 4
• Consider hospitalization for close monitoring 1

Follow-Up and Monitoring

• Elevate the injured body part to reduce swelling and accelerate healing 1
• Follow up within 24 hours by phone or office visit for all outpatients 1
• Hospitalize if infection progresses despite appropriate antimicrobial therapy 1

Common Pitfalls to Avoid

• Do not assume human bites are benign—20-25% become infected, with polymicrobial flora including Eikenella corrodens, which is unique to human bites 2, 5
• Do not close wounds primarily (except facial wounds) even if they appear clean—infection risk remains high 1
• Do not miss clenched-fist injuries, which may appear as minor lacerations over the metacarpophalangeal joints but represent deep penetrating trauma 1, 4
• Do not give antibiotics for late presentations (>24 hours) without signs of infection—this is not supported by evidence 2