What is the treatment for a patient with a suspected infected thumb laceration and bruising on the upper bicep, who has not had a recent tetanus (Td) vaccination and has a history of a small cut from picking up glass a week ago?

Treatment of Suspected Infected Thumb Laceration with Unknown Tetanus Status

This patient requires immediate wound evaluation and culture, empiric antibiotics covering skin flora and potential glass-contamination organisms, tetanus toxoid (Tdap preferred), and consideration of tetanus immune globulin (TIG) if the primary vaccination series was never completed.

Wound Assessment and Management

Initial Wound Care

• Thoroughly irrigate and debride the wound to remove any retained glass fragments and necrotic tissue, as surgical debridement is essential for eliminating the source of infection and preventing tetanus toxin production 1.
• Obtain wound cultures before initiating antibiotics to identify the causative organisms, as empirical therapy often misses pathogens in contaminated wounds 1.
• Do not primarily close this wound - a one-week-old contaminated laceration with suspected infection should remain open with sterile dressing changes; primary closure is contraindicated except for facial wounds 1.

Antibiotic Selection

• Initiate amoxicillin-clavulanate 875 mg twice daily as first-line therapy for infected hand wounds from glass contamination 1.
• This covers the typical polymicrobial flora including streptococci, Staphylococcus aureus, and anaerobes that commonly infect traumatic wounds 1.
• Alternative regimens if penicillin-allergic: moxifloxacin as monotherapy OR ciprofloxacin/levofloxacin plus metronidazole 1.
• Continue antibiotics for 7-10 days depending on clinical response 2.

Tetanus Prophylaxis - Critical Decision Point

For Patients with Unknown/Uncertain Vaccination History

Treat this patient as having received NO previous tetanus toxoid doses - this is the standard approach when vaccination history cannot be verified 1, 3.

Immediate Tetanus Management

• Administer Tdap (tetanus-diphtheria-pertussis) immediately - this is strongly preferred over Td if the patient has never received Tdap as an adult 1, 4.
• Administer Tetanus Immune Globulin (TIG) 250 units IM at a separate injection site using a different syringe, as this wound is contaminated and the patient has uncertain vaccination history 1, 3.
• TIG provides immediate passive immunity by neutralizing circulating toxin, while the toxoid stimulates active immunity that takes time to develop 5, 3.

Rationale for Both TIG and Toxoid

The combination is necessary because:

• This is a "dirty wound" (glass contamination, one week old, potentially infected) requiring prophylaxis if >5 years since last dose OR if vaccination history is incomplete 1.
• TIG provides immediate protection that the patient needs now, while tetanus toxoid provides future protection 1, 5.
• Patients with incomplete primary series require both for adequate prophylaxis in contaminated wounds 1.

Complete the Primary Series

• Schedule the second dose of Td or Tdap at least 4 weeks after today's dose 5.
• Schedule the third dose 6-12 months after the second dose to complete the primary series 5.
• Document this clearly, as failure to complete the series leaves the patient vulnerable to future tetanus exposure 5, 3.

Evaluation of Upper Bicep Bruising

Assess for Compartment Syndrome or Deep Infection

• Examine for signs of deep space infection: increasing pain, swelling, erythema tracking proximally, fever, or systemic toxicity 1.
• Evaluate neurovascular status of the entire upper extremity to rule out compartment syndrome or vascular injury.
• Consider imaging (ultrasound or MRI) if there is concern for deep abscess, retained foreign body, or necrotizing infection 1.

Management Based on Findings

• If simple contusion: observe with close follow-up in 24-48 hours 2.
• If abscess identified: incision and drainage is the primary treatment, with antibiotics added for surrounding cellulitis or if drainage alone is inadequate 2.
• If necrotizing infection suspected: immediate surgical consultation for debridement and broad-spectrum IV antibiotics 1.

Common Pitfalls to Avoid

• Do not assume the bruising is unrelated - glass injuries can cause tracking infections or hematomas that become secondarily infected 2.
• Do not delay TIG administration while waiting to clarify vaccination history - err on the side of giving it for contaminated wounds with uncertain history 1.
• Do not confuse routine 10-year boosters with wound management protocols - contaminated wounds require prophylaxis if >5 years since last dose, and TIG if primary series incomplete 1, 6.
• Do not give only tetanus toxoid without TIG in patients with incomplete vaccination history and dirty wounds - this provides inadequate immediate protection 1.
• Do not close this wound - infected wounds and puncture wounds should not be sutured as this increases infection risk 1, 2.

Follow-Up Requirements

• Reassess wound in 24-48 hours for clinical improvement; if worsening despite antibiotics, consider MRSA and broaden coverage 2.
• Ensure completion of tetanus vaccination series at appropriate intervals, as natural infection does NOT confer immunity 5, 3.
• Monitor for signs of tetanus over the next 3-21 days (median 8 days), though this is rare with appropriate prophylaxis: jaw stiffness, difficulty swallowing, muscle spasms 5, 7.