What is the best course of treatment for a female patient with a swollen right finger and hand after being bitten by a pet dog?

Dog Bite to Finger with Hand Swelling: Treatment Approach

This patient requires immediate antibiotic therapy with amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days, given the high-risk features of hand involvement and established edema. 1

Immediate Management

Wound Care

• Irrigate the wound thoroughly with sterile normal saline to remove debris and reduce bacterial load—this is one of the most critical interventions 1
• Remove superficial debris only; avoid aggressive debridement that could enlarge the wound or impair closure 1
• Do not close infected wounds or wounds with established swelling 1
• Elevate the affected hand using a sling to reduce swelling and accelerate healing 1

Antibiotic Therapy - Critical Decision Point

This patient meets multiple high-risk criteria mandating antibiotic treatment: 1

• Hand involvement (high-risk anatomic location)
• Established edema extending beyond the bite site
• Likely presenting >8-12 hours after injury (given progression to hand swelling)

First-line antibiotic: Amoxicillin-clavulanate 875/125 mg orally twice daily for 3-5 days 1

This agent provides coverage against:

• Pasteurella multocida (present in 50% of dog bites) 1
• Staphylococci and streptococci (40% of dog bites) 1
• Anaerobes including Bacteroides, Fusobacterium, and Prevotella species 1

Alternative Antibiotics (if penicillin allergy)

• Doxycycline 100 mg twice daily (excellent Pasteurella coverage but some streptococci resistant) 1
• Moxifloxacin 400 mg daily (monotherapy option with anaerobic coverage) 1
• Avoid cephalexin, dicloxacillin, macrolides, or clindamycin monotherapy—all have poor activity against Pasteurella multocida 1

Critical Red Flags Requiring Urgent Evaluation

Assess immediately for complications that necessitate hospitalization or surgical consultation: 1

• Pain disproportionate to injury (suggests periosteal penetration or deep infection) 1
• Inability to move the finger (possible tendon injury or septic arthritis) 1
• Rapidly progressive swelling or erythema spreading up the arm
• Systemic symptoms: fever, chills, or signs of sepsis 2
• Purulent drainage or abscess formation 1

Why Hand Bites Are High-Risk

Hand wounds carry significantly higher infection rates and complication risks than bites to fleshy body parts 1. The confined anatomic spaces facilitate spread to joints, tendons, and bone. Dog bites to hands can result in: 1, 3

• Septic arthritis (requiring 3-4 weeks of antibiotics)
• Osteomyelitis (requiring 4-6 weeks of antibiotics)
• Tenosynovitis
• Compartment syndrome

Additional Essential Interventions

Tetanus Prophylaxis

Administer tetanus toxoid 0.5 mL intramuscularly if: 1

• Last tetanus vaccination >5 years ago for contaminated wounds
• Last vaccination >10 years ago for clean wounds
• Vaccination status unknown

Rabies Assessment

Rabies prophylaxis is generally NOT needed for pet dog bites unless: 1

• The dog's vaccination status is unknown or inadequate
• The dog exhibits abnormal behavior
• Local health department recommends it based on regional rabies prevalence

Consult local health officials to determine if post-exposure prophylaxis is indicated 1

Follow-Up Protocol

Mandatory reassessment within 24 hours (phone or in-person) to evaluate: 1

• Response to antibiotics
• Progression of swelling or erythema
• Development of purulent drainage
• Worsening pain or fever

Consider hospitalization for IV antibiotics if: 1

• Infection progresses despite oral antibiotics
• Patient develops systemic signs
• Deep space infection suspected
• Patient is immunocompromised, asplenic, or has advanced liver disease 1

IV Antibiotic Options (if hospitalization required)

• Ampicillin-sulbactam 1.5-3.0 g every 6-8 hours 1
• Piperacillin-tazobactam 3.37 g every 6-8 hours 1
• Carbapenems (ertapenem, imipenem, meropenem) 1

Common Pitfalls to Avoid

• Do not use first-generation cephalosporins (cephalexin) or penicillinase-resistant penicillins alone—they miss Pasteurella 1
• Do not delay antibiotics in hand bites waiting to see if infection develops—preemptive therapy is indicated 1
• Do not underestimate seemingly minor puncture wounds—these can penetrate joints or bone 1
• Do not suture infected or swollen wounds—this traps bacteria and worsens infection 1
• Be aware that Capnocytophaga canimorsus can cause life-threatening sepsis, particularly in asplenic or immunocompromised patients 1, 2