Infection occurs in 6% to 11% of puncture wounds, with Staphylococcus aureus predominating (including methicillin-resistant S. aureus—MRSA). Pseudomonas aeruginosa is the most frequent etiologic agent in post-puncture wound osteomyelitis, particularly when penetration occurs through the sole of an athletic shoe. Post-puncture wound infections with treatment failure suggest the presence of a retained foreign body.
Clinical Features (See Also Chapter 9)
Wounds older than 6 hours with large and deep penetration and obvious visible contamination, which occurred outdoors with penetration through footwear, carry the highest risk of infectious complications. Patients with a history of diabetes mellitus, peripheral vascular disease, immunosuppression, or advanced age are at increased risk of infection.
On physical examination, the likelihood of injury to structures beneath the skin must be determined. Distal function of tendons, nerves, and vessels should be assessed carefully. The site should be inspected for location, condition of the surrounding skin, and the presence of foreign matter, debris, or devitalized tissue. Infection is suggested when there is evidence of pain, swelling, erythema, warmth, fluctuance, decreased range of motion, or drainage from the site.
Diagnosis and Differential
Multiple view, “soft tissue,” plain film radiographs should be obtained of all infected puncture wounds and of any wound suspicious for a retained foreign body (see Chapter 14 for recommendations on the diagnosis and management of retained foreign bodies).
Emergency Department Care and Disposition
Many aspects of the treatment of puncture wounds remain controversial.
Uncomplicated, clean punctures less than 6 hours after injury require only low-pressure irrigation and tetanus prophylaxis, as indicated. Soaking has no proven benefit. Healthy patients do not appear to require prophylactic antibiotics.
Prophylactic antibiotics may benefit patients with peripheral vascular disease, diabetes mellitus, and immunosuppression. Plantar puncture wounds, deeper wounds, especially those in high-risk patients, or through athletic shoes should be treated with prophylactic antibiotics. Fluoroquinolones (such as ciprofloxacin 500 milligrams twice daily) are recommended for plantar wounds and are acceptable alternatives to parenteral administration of a cephalosporin and aminoglycoside. For other at risk wounds, cephalexin 500 milligrams four times daily, or a macrolide, are recommended. In general, prophylactic antibiotics should be continued for 5 to 7 days.
Ciprofloxacin is not recommended for routine use in children for prophylaxis. Cephalexin 12.5 to 25 milligrams/kilogram/dose 4 times daily up to 500 milligrams/dose can be used with close follow-up.
Wounds infected at presentation need to be differentiated into cellulitis, abscess, deeper spreading soft tissue infections, and bone or cartilage involvement. Plain radiographs are indicated to detect the possibility of radiopaque foreign body, soft tissue gas, or osteomyelitis. Bedside ultrasound may identify abscess.
Cellulitis usually is localized without significant drainage, developing within 1 to 4 days. There is no need for routine cultures, and antimicrobial coverage should be directed at gram-positive organisms, especially S. aureus. Seven to ten days of a cephalexin (dose above) is usually ...