What is the recommended antibiotic regimen for a dog bite with swollen neck symptoms in a patient allergic to Penicillin (PCN)?

Antibiotic Treatment for Dog Bite with Swollen Neck in PCN-Allergic Patient

For a dog bite with swollen neck symptoms in a patient allergic to penicillin, doxycycline is the recommended first-line antibiotic treatment. 1

Antibiotic Options for PCN-Allergic Patients

First-Line Treatment

• Doxycycline: 100 mg orally twice daily for 7-14 days 1, 2
  • Excellent coverage against common dog bite pathogens including Pasteurella multocida
  • Appropriate dosing: 200 mg on first day (100 mg every 12 hours), then 100 mg twice daily 2
  • Duration depends on severity: 7-10 days for localized infection, 10-14 days for more severe infections 1

Alternative Options

1. Fluoroquinolone (e.g., ciprofloxacin) plus clindamycin 3, 1

   • Provides coverage against both aerobic and anaerobic bacteria
   • Important for mixed infections commonly seen in dog bites

2. Trimethoprim-sulfamethoxazole plus clindamycin 1

   • Alternative when fluoroquinolones are contraindicated

Important Considerations

Avoid These Antibiotics

• First-generation cephalosporins (e.g., cephalexin)
• Penicillinase-resistant penicillins (e.g., dicloxacillin)
• Macrolides (e.g., erythromycin)
• Clindamycin alone

These antibiotics have poor activity against Pasteurella multocida, which is present in approximately 50% of dog bite wounds 3, 1.

Wound Management

1. Thorough cleansing with sterile normal saline
2. Remove superficial debris
3. Do not close infected wounds, especially if presenting >8 hours after injury 1
4. Elevate the affected area to reduce swelling

Special Considerations for Neck Involvement

• Swelling in the neck requires careful monitoring for:
  • Airway compromise
  • Deep space infections
  • Potential for rapid progression

When to Consider IV Antibiotics/Hospitalization

• Severe infection with systemic symptoms
• Deep neck space involvement
• Immunocompromised patient
• Significant swelling affecting airway

Follow-up Care

• Reassess within 24-48 hours 1
• Monitor for signs of worsening infection
• Consider extending antibiotic duration if infection is slow to resolve

Duration of Treatment

• Uncomplicated infections: 7-10 days
• Severe or systemic infections: 10-14 days
• Complicated infections (osteomyelitis, septic arthritis): 3-4 weeks 1

The evidence strongly supports doxycycline as an effective option for penicillin-allergic patients with dog bite wounds, providing excellent coverage against the common pathogens including Pasteurella multocida, which is frequently missed by other antibiotic choices 3, 1.