Felon

Background

• Subcutaneous pyogenic infection of the pulp space compartments of the distal finger
• Do not mistake for pulp erythema due to Paronychia or Herpetic Whitlow
• Infection typically begins w/ minor trauma to dermis overlying finger pad
  • May spread to flexor tendon sheath, IP joint, or underlying periosteum

Clinical Features

• Red, tense, and markedly painful distal pulp space

Diagnosis

• Gram stain and culture (chronic infections may be caused by atypical organisms)

Differential Diagnosis

Hand and finger infections

• Bed bugs
• Closed fist infection (Fight Bite)
• Hand cellulitis
• Hand deep space infection
• Hand-foot-and-mouth disease
• Herpetic whitlow
• Felon
• Flexor tenosynovitis
• Paronychia
• Scabies
• Sporotrichosis

Look-Alikes

• Digital mixoid cyst

Treatment

• Incision and drainage (see image below)
  • Number 11 blade is used to make incision on nonoppositional side of affected digit
    • Start incision 5 mm distal to flexor DIP crease
    • End incision 5mm proximal to nail plate border
  • Bluntly dissect and explore wound until abscess is decompressed
  • Pack w/ sterile gauze
• Instruct pt to keep extremity elevated
• Abx indicated for felons associated w/ cellulitis
• Dispo f/u in 2 days for wound check
  • ortho only if complications

See Also

Hand Infection

Source

• Clark, DC. Common Acute Hand Infections. Am Fam Physician 2003;68:2167-76