What is the recommended treatment for a patient with a pig bite, considering potential exposure to zoonotic diseases and risk of infection?

Pig Bite Treatment

Treat pig bites with immediate copious irrigation, amoxicillin-clavulanate as first-line antibiotic prophylaxis, tetanus prophylaxis if indicated, and rabies risk assessment based on local epidemiology and animal vaccination status.

Immediate Wound Management

• Irrigate the wound immediately with copious amounts of sterile normal saline or running tap water using a 20-mL or larger syringe to generate adequate pressure and remove all visible debris 1, 2.
• Running tap water is as effective as sterile saline and superior to antiseptic solutions like povidone-iodine for irrigation 1.
• Remove only superficial debris; avoid aggressive debridement that causes additional tissue damage 1, 2.
• Explore the wound for potential tendon, bone, or joint involvement, particularly in hand injuries 2.

Wound Closure Decisions

• Do not close pig bite wounds except for facial lacerations, as most bite wounds should heal by secondary intention 1, 3.
• Infected wounds or wounds presenting >8 hours after injury should never be closed 1, 3.
• Facial wounds may be closed primarily after meticulous irrigation and concurrent prophylactic antibiotics 1, 3.
• For clean, early-presenting wounds (<8 hours), consider approximation with Steri-Strips rather than sutures 1.

Antibiotic Prophylaxis and Treatment

• Amoxicillin-clavulanate (875/125 mg twice daily) is the first-line antibiotic for pig bites, providing broad-spectrum coverage against oral flora and potential pathogens 4, 1, 3.
• Prophylactic antibiotics are mandatory for hand wounds, puncture wounds, wounds presenting >8 hours after injury, immunocompromised patients, and wounds with crush injury or devitalized tissue 1, 5.
• Treatment duration is 3-5 days for prophylaxis and 7-10 days for established infection 3.

Alternative Antibiotic Regimens for Penicillin-Allergic Patients:

• Doxycycline 100 mg twice daily 4, 3
• Penicillin VK plus dicloxacillin 4
• Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) plus metronidazole or clindamycin 4, 1

Avoid These Antibiotics:

• Do not use first-generation cephalosporins, macrolides, or clindamycin monotherapy due to poor coverage against potential pathogens in animal bites 1, 3.

Severe Infections Requiring IV Therapy:

• Ampicillin-sulbactam or piperacillin-tazobactam as first-line IV therapy 4, 3
• Second-generation cephalosporins (cefoxitin) or carbapenems (ertapenem, imipenem, meropenem) as alternatives 4, 3
• Extended therapy for 3-4 weeks for septic arthritis and 4-6 weeks for osteomyelitis 4, 3

Tetanus Prophylaxis

• Administer tetanus toxoid (0.5 mL intramuscularly) if vaccination status is outdated or unknown 4, 1, 3.
• Give booster if >5 years since last dose for contaminated wounds (all pig bites qualify) or >10 years for clean wounds 1, 3.

Rabies Risk Assessment and Prophylaxis

• Rabies risk from pig bites depends on geographic location, circumstances of attack, and vaccination status of the animal 1, 2.
• Pigs are not typical rabies vectors, but risk assessment should be performed based on local epidemiology and whether the pig was vaccinated 1, 6.
• For suspected rabies exposure in previously unvaccinated persons, administer rabies immune globulin (HRIG) on day 0 and rabies vaccine on days 0,3,7,14, and 28 4, 1.
• Begin vaccination immediately without waiting for animal observation results 1.
• Never administer rabies vaccine in the gluteal area due to lower antibody titers 1.

Zoonotic Disease Considerations Specific to Pigs

• Pigs can transmit multiple zoonotic pathogens including Sarcoptes scabiei (skin mites), swine influenza viruses, and pathogens from reproductive fluids 7.
• Swine influenza transmission to humans has been documented sporadically, particularly at agricultural fairs 7.
• Consider Q fever (Coxiella burnetii), leptospirosis, listeriosis, and brucellosis if exposure to reproductive materials occurred 7.
• Skin irritation from Sarcoptes scabiei can be self-limiting but may cause itching for multiple days 7.

Follow-Up and Monitoring

• Elevate the injured extremity to reduce swelling and accelerate healing 4, 1, 3.
• Follow up within 24 hours by phone or office visit for all outpatients 4, 1, 3.
• Monitor for signs of infection including increasing pain, redness, swelling, purulent discharge, or fever 1.
• Hospitalize if infection progresses despite appropriate antibiotics or if deep tissue involvement is suspected 4, 3.

Critical Pitfalls to Avoid

• Do not delay medical evaluation for pig bite wounds, as early intervention reduces infection risk 1.
• Do not use antiseptic solutions for irrigation; water or saline is superior 1.
• Do not close wounds >8 hours old or any contaminated wounds 1, 3.
• Hand wounds are at highest risk for complications and always warrant antibiotic prophylaxis 1, 5.
• Do not wait for animal observation results before initiating rabies prophylaxis if exposure is suspected 1.