A 25-year-old man comes to the office due to right hand pain and swelling. He injured the skin over his right knuckles when he punched a man in the teeth during a bar fight 3 days ago. The patient ignored the wound initially, but his hand became more painful and swollen yesterday. He has no medical history and takes no medications. The patient received a tetanus toxoid vaccination at age 18. Temperature is 37.3 C (99.1 F), blood pressure is 120/70 mm Hg, and pulse is 78/min. There are small lacerations over the right third and fourth metacarpophalangeal joints with surrounding erythema, swelling, and tenderness. No discharge or crepitus is present. Hand radiographs reveal no foreign body or bone/joint changes. Cultures are obtained. Which of the following empiric antibiotics is most appropriate for this patient?

Question

A 25-year-old man comes to the office due to right hand pain and swelling.  He injured the skin over his right knuckles when he punched a man in the teeth during a bar fight 3 days ago.  The patient ignored the wound initially, but his hand became more painful and swollen yesterday.  He has no medical history and takes no medications.  The patient received a tetanus toxoid vaccination at age 18.  Temperature is 37.3 C (99.1 F), blood pressure is 120/70 mm Hg, and pulse is 78/min.  There are small lacerations over the right third and fourth metacarpophalangeal joints with surrounding erythema, swelling, and tenderness.  No discharge or crepitus is present.  Hand radiographs reveal no foreign body or bone/joint changes.  Cultures are obtained.  Which of the following empiric antibiotics is most appropriate for this patient?

Quizplus · Accepted Answer

This patient experienced a bite wound from a clenched fist ("fight-bite") injury. Human bite wounds are prone to polymicrobial infection with aerobic and anaerobic oral flora. The most common organisms include streptococci, Staphylococcus aureus, Eikenella corrodens, Haemophilus influenzae, and beta-lactamase-producing anaerobic bacteria. Patients often initially ignore a wound until pain, swelling, or purulent discharge develops. Blood and wound cultures should be sent; empiric antibiotics are required. Although large studies on empiric antibiotic selection for human bite wounds are scarce, amoxicillin-clavulanate is often the treatment of choice due to excellent coverage of gram-positive, gram-negative, and beta-lactamase-producing oral anaerobic organisms (as clavulanate is a beta-lactamase inhibitor). Surgical debridement is usually necessary, and wounds are typically left open to drain and heal by secondary intention (due to high infection risk with closure). Tetanus vaccination should be administered to those who are not up to date. (Choice B) Ampicillin can be used for upper respiratory tract infections (eg, pharyngitis) and is effective against many gram-positive and gram-negative organisms. However, it does not provide coverage for beta-lactamase-producing flora and is often combined with the beta-lactamase inhibitor sulbactam in an intravenous formulation. (Choice C) Ciprofloxacin covers many gram-negative organisms and some gram-positive organisms (excluding most streptococci), but it does not provide reliable coverage for anaerobic organisms. It is often used for genitourinary and gastrointestinal infections. (Choice D) Clindamycin is effective against gram-positive bacteria and anaerobes but not against most gram-negative organisms (eg, Eikenella corrodens). It is used for some lung abscesses, skin and soft-tissue infections, and female upper reproductive tract infections (anaerobic coverage in combination with other agents). (Choice E) Erythromycin is sometimes used as a second-line agent in the treatment of gonococcal or chlamydial urethritis. Erythromycin covers some atypical organisms (eg, Mycoplasma), but overall it does not provide adequate gram-negative or anaerobic coverage. Educational objective: Human bite wounds often result in polymicrobial infections with aerobic and anaerobic oral organisms. Empiric treatment with amoxicillin-clavulanate provides adequate coverage for the majority of virulent oral bacteria.

A 25-Year-Old Man Comes to the Office Due to Right