Puncture wound

A puncture wound is a penetrating injury caused by a sharp, narrow object (nail, needle, tack, glass, wood, thorn) that creates a small entry wound with potential deep tissue inoculation. The foot is the most common site. The primary ED concerns are retained foreign body, tetanus prophylaxis, and risk of deep infection — including Pseudomonas osteomyelitis after nail-through-shoe injuries.

Background

• Infection rate: 6–11% of puncture wounds overall
• Staphylococcus aureus (including MRSA) is the most common infecting organism in early wound infections
• Pseudomonas aeruginosa is the most common organism in post-puncture osteomyelitis, classically associated with nail penetration through an athletic shoe (Pseudomonas colonizes the foam insole)
• Osteomyelitis incidence after plantar puncture: estimated 0.04–1.6%, but devastating when it occurs
• Metatarsal heads are the highest-risk location for osteomyelitis (thin soft tissue overlying bone)

Clinical Features

History — key questions

• What caused the injury? (nail, needle, glass, wood, thorn, marine organism)
• Through footwear? Nail through a rubber-soled shoe/sneaker greatly increases Pseudomonas risk
• When did it happen? Wounds >6 hours old carry higher infection risk
• Where? Outdoor, barnyard, or contaminated environment increases risk
• Depth of penetration? Did the patient feel it hit bone? Was the full length of the nail embedded?
• What was removed? Could any fragment have been retained?
• Tetanus immunization status?
• Comorbidities? Diabetes, peripheral artery disease, immunosuppression, chronic steroid use — all increase infection risk significantly

Acute presentation (fresh wound)

• Small entry wound — deceptively minor in appearance
• Pain and tenderness at the wound site
• Bleeding is often minimal (small entry point seals quickly)
• Foreign body sensation or inability to fully bear weight

Delayed presentation (infected wound)

• 1–4 days: Cellulitis — localized erythema, warmth, swelling, increasing pain. Most commonly S. aureus or Streptococcus
• 4–7 days: Deep soft tissue infection, abscess, spreading cellulitis, septic arthritis. Failure to respond to antibiotics should prompt concern for retained foreign body
• 7–14+ days: Osteomyelitis or osteochondritis — classic presentation: patient initially improved after the acute wound, then re-presents with increasing foot pain, difficulty weight-bearing, mild local swelling, but minimal systemic symptoms (often afebrile with normal WBC)

Differential Diagnosis

• Retained foreign body (the #1 cause of treatment failure)
• Cellulitis
• Abscess
• Osteomyelitis / osteochondritis
• Septic arthritis
• Necrotizing soft tissue infections
• Tendon injury or tendon laceration
• Compartment syndrome (rare, with deep penetrating wounds)
• Plantar fascia injury
• Marine envenomation or spine injury (marine puncture wounds)

Evaluation

Workup

All puncture wounds:

• Careful wound exploration — assess wound depth and trajectory. Palpate for retained material. The small entry point can hide significant deep tissue injury
• Neurovascular and tendon exam — check distal sensation, capillary refill, and active range of motion of all toes/digits distal to the wound
• Tetanus status — update per tetanus prophylaxis guidelines

Imaging for foreign body:

• Plain radiographs — obtain for all foot puncture wounds. Detect: radiopaque foreign bodies (metal, glass, gravel, bone fragments), soft tissue gas, periosteal changes (if delayed presentation)
  • Metal, glass ≥2 mm, and gravel are typically visible on X-ray
  • Wood, thorns, plastic, and rubber are radiolucent and will NOT be seen on X-ray
• Ultrasound — excellent for detecting non-radiopaque foreign bodies (wood, plastic, thorns). Sensitivity ~90% for superficial foreign bodies. Also useful for identifying fluid collections/abscess
• CT — if high suspicion for retained foreign body not seen on X-ray or ultrasound
• MRI — best for evaluating suspected osteomyelitis, deep soft tissue infection, or septic arthritis in delayed presentations. MRI is not needed acutely for uncomplicated wounds

Infected wounds:

• CBC, basic metabolic panel, ESR, CRP
• Wound culture (deep tissue preferred over superficial swab) if purulent or deep infection
• Blood cultures if systemic signs
• Plain radiographs — look for osteolytic changes, periosteal reaction, gas
• MRI if concern for osteomyelitis, deep abscess, or septic arthritis

Diagnosis

• Puncture wound diagnosis is clinical
• Suspect retained foreign body in any wound that fails to improve or worsens despite antibiotics
• Suspect osteomyelitis in any patient re-presenting 1–3 weeks after a plantar puncture with increasing foot pain and difficulty bearing weight, especially after nail-through-shoe mechanism

Management

Acute wound care

• Wound preparation: Cleanse the skin surrounding the wound with antiseptic. Remove any visible debris
• Coring/unroofing: For deep plantar puncture wounds, consider excising a small ellipse of skin (2–3 mm) around the puncture site to allow adequate exploration, irrigation, and drainage. This is especially important for wounds >6 hours old or through footwear. Use local anesthesia (posterior tibial nerve block or local infiltration)
• Irrigation: High-pressure irrigation of deep puncture wounds is debated — some evidence suggests it may push contaminants deeper. Low-pressure irrigation of the wound tract after coring is reasonable. Do NOT close puncture wounds
• Foreign body removal: Remove any identified foreign body. If deeply embedded, consider procedural sedation or surgical consultation
• Do NOT close puncture wounds — leave open to heal by secondary intention
• Non-weight-bearing or protective footwear: Instruct the patient to minimize weight-bearing on the affected foot for 24–48 hours

Tetanus prophylaxis

• Puncture wounds are tetanus-prone wounds
• Administer Td or Tdap if last booster was >5 years ago
• If immunization history unknown or <3 doses received, give Td/Tdap AND tetanus immune globulin (TIG)

Antibiotics

Uncomplicated superficial puncture wounds:

• Prophylactic antibiotics are NOT routinely indicated for clean, superficial puncture wounds presenting early
• Close follow-up at 48 hours is more important than prophylactic antibiotics

Higher-risk wounds (consider prophylactic antibiotics):

• Deep plantar wounds, especially through footwear (sneaker/shoe)
• Wounds >6 hours old with significant contamination
• Diabetes, PAD, immunosuppression
• Wounds with incomplete foreign body removal
• Adults:
  • Through footwear (Pseudomonas risk): Ciprofloxacin 500 mg PO BID × 5–7 days
  • Other high-risk wounds: Cephalexin 500 mg PO QID × 5–7 days (covers Staph/Strep)
• Children:
  • Cephalexin 25 mg/kg/dose PO QID (max 500 mg/dose)
  • Fluoroquinolones are relatively contraindicated in children for prophylaxis; reserve for established Pseudomonas infection with ID guidance
• Duration: 5–7 days for prophylaxis

Infected wounds at presentation:

• Early cellulitis (1–4 days): Anti-staphylococcal coverage. Cephalexin or clindamycin (add TMP-SMX or doxycycline if MRSA risk)
• Deep or spreading infection: IV antibiotics covering Staph (including MRSA), Strep, and Pseudomonas:
  • Vancomycin 15–20 mg/kg IV + ceftazidime 1–2 g IV q8h (or ciprofloxacin 400 mg IV q12h)
• Suspected osteomyelitis: Surgical consultation for debridement + IV antibiotics (vancomycin + anti-pseudomonal beta-lactam). Definitive culture-directed therapy guided by operative specimens

Disposition

• Discharge with 48-hour wound check: Clean, superficial wounds; reliable patient; no high-risk features; tetanus up to date
• Discharge with antibiotics and 48-hour follow-up: Higher-risk wounds (deep, through footwear, diabetic/immunocompromised)
• Admit: Progressive cellulitis with lymphangitis or systemic signs; deep space abscess; suspected septic arthritis or osteomyelitis; immunocompromised patients with spreading infection; need for IV antibiotics or operative debridement
• Surgical/orthopedic consultation: Deeply embedded foreign body requiring operative removal; suspected osteomyelitis; septic arthritis; deep compartment involvement

Discharge instructions — critical points

• Return if: Increasing pain, swelling, redness, fever, red streaking, inability to bear weight, drainage from the wound, or failure to improve within 48 hours
• Warn about delayed osteomyelitis: Even with proper care, infection of the bone may develop 1–3 weeks later. Return for any new or worsening foot pain, especially difficulty walking, even if the original wound appeared to be healing
• Soak vs. no soak: Routine soaking is no longer recommended. Keep the wound clean and dry
• Footwear: Avoid constrictive shoes; wear open or protective footwear until healed

See Also

• Cellulitis
• Osteomyelitis
• Septic arthritis
• Tetanus
• Diabetic foot ulcer
• Diabetic foot infection
• Wound management
• Foreign body

External Links

• PEM Morsels: Plantar Puncture Wound