What is the recommended bacterial treatment order for abrasions with a high risk of infection?

Antibiotic Treatment for High-Risk Abrasions

For traumatic abrasions with high infection risk, initiate a broad-spectrum topical antibiotic immediately—specifically amoxicillin-clavulanate for animal/human bite-related wounds, or a fluoroquinolone for corneal abrasions, particularly in contact lens wearers. 1, 2

Risk Stratification: When Antibiotics Are Indicated

Prophylactic antibiotics are strongly recommended for abrasions in the following high-risk scenarios:

• Corneal abrasions following trauma: Broad-spectrum topical antibiotics prevent both bacterial and fungal infection when started within 24 hours 1
• Contact lens-associated corneal abrasions: Require antipseudomonal coverage due to Pseudomonas risk 1, 3
• Animal or human bite wounds: Immediate medical evaluation and antibiotics are essential due to polymicrobial contamination 1, 2
• Wounds contaminated with saliva (human or animal): High infection risk mandates early antibiotic administration 1, 2
• Deep wounds or wounds on hands, feet, face, genitals, or near joints: These anatomic locations carry elevated infection risk 1, 2

Specific Antibiotic Recommendations by Wound Type

Corneal Abrasions

For non-contact lens wearers:

• Topical fluoroquinolone eye drops are preferred as monotherapy, equally effective as fortified combination therapy 1
• Dosing: Loading dose every 5-15 minutes, then hourly for severe cases 1
• Avoid patching or therapeutic contact lenses in contact lens-associated abrasions due to increased keratitis risk 1

For contact lens wearers:

• Antipseudomonal topical antibiotics are mandatory 1, 3
• Fluoroquinolones provide appropriate Pseudomonas aeruginosa coverage 1

Animal/Human Bite Wounds and Contaminated Abrasions

First-line therapy:

• Amoxicillin-clavulanate provides optimal coverage for polymicrobial flora including Pasteurella multocida, streptococci, staphylococci, and anaerobes 2
• Duration: 5-7 days for uncomplicated wounds with proper debridement 2
• Severe or contaminated wounds may require 7-10 days 2

Penicillin allergy alternatives:

• Mild allergy: Cefuroxime (covers P. multocida but limited anaerobic coverage) 2
• Severe allergy: Doxycycline (excellent P. multocida activity and broad pathogen coverage) 2, 4

Special consideration for marine animal injuries:

• Doxycycline or tetracycline is preferred due to Mycoplasma species risk in pinniped (seal/sea lion) bites 5, 4
• Treatment failure with amoxicillin-clavulanate suggests Mycoplasma infection 4

General Skin Abrasions (Non-Bite)

High-risk features requiring antibiotics:

• Wounds presenting >24 hours after injury with infection signs 1
• Deep wounds with tissue damage or significant soil contamination 1, 2
• Patients with severe comorbidities or immunocompromise 1

Antibiotic selection:

• Broad-spectrum coverage for aerobic and anaerobic organisms 1
• Consider anaerobic coverage (including Clostridium species) for soil-contaminated wounds 2

Critical Management Principles

Wound Preparation (Essential Before Antibiotics)

• Thorough irrigation until no debris remains—use running tap water or sterile saline rather than antiseptic agents 1
• Debridement of necrotic tissue to reduce bacterial burden 2
• Avoid high-pressure irrigation as it may drive bacteria deeper into tissue 1

When NOT to Use Antibiotics

• Simple superficial abrasions without high-risk features 1
• Bite wounds presenting ≥24 hours post-injury without infection signs 1
• Chronic epithelial defects (controversial—may promote resistant organisms) 1

Monitoring and Follow-Up

Indications for immediate medical evaluation:

• Development of redness, swelling, foul-smelling drainage, increased pain, or fever 1
• Corneal abrasions with worsening symptoms after 48-72 hours 1
• Any penetrating injury or vision changes 3

Follow-up timing:

• Small (<4mm) uncomplicated corneal abrasions with resolving symptoms may not require follow-up 3
• All other patients should be reevaluated within 24 hours 3

Common Pitfalls to Avoid

• Do not patch corneal abrasions, especially in contact lens wearers—this increases bacterial keratitis risk 1
• Do not use amoxicillin alone for bite wounds—the clavulanate component is essential for beta-lactamase producing organisms 2
• Do not delay antibiotics for high-risk wounds—efficacy depends on initiation within 24 hours 1
• Do not use topical antibiotics routinely on clean superficial skin abrasions—occlusive dressings without antibiotics heal equally well 1
• Avoid broad gram-negative coverage for simple cellulitis—this represents potentially avoidable antibiotic exposure 6

Adjunctive Measures

• Tetanus prophylaxis if not vaccinated within 10 years (Tdap preferred if not previously given) 2
• Occlusive dressings (film, petrolatum, hydrogel) promote healing better than dry dressings for clean wounds 1
• Pain control with topical NSAIDs or oral analgesics for corneal abrasions 3