Felon

1. See Also
   1. Paronychia
   2. Hand Infection
2. Definition
   1. Infection of closed space of distal phalanx pulp
3. Mechanism: Local finger tip Puncture Wound
   1. Splinter
   2. Glass fragment
   3. Punctures (e.g. Finger-stick blood sugar testing)
4. Symptoms
   1. Rapidly increasing pressure and pain at finger tip
   2. Thumb and index finger most commonly affected
5. Differential Diagnosis
   1. Paronychia
   2. Herpetic Whitlow
   3. Cellulitis
   4. Tuft Fracture
6. Complications
   1. Osteomyelitis of distal phalanx
   2. Contiguous spread
      1. Pyogenic Flexor Tenosynovitis
      2. Infection of adjacent joint
7. Management: Conservative measures
   1. Tetanus prophylaxis
   2. Warm soaks
   3. Antibiotics for 5 to 14 days
      1. Cephalexin (Keflex) or
      2. Dicloxacillin
8. Management: Early Incision and Drainage
   1. Indications
      1. No improvement after 24 hours conservative therapy
   2. Contraindications
      1. Herpetic Whitlow
   3. Anesthesia
      1. Digital Block (Metacarpal Block)
   4. Technique
      1. Apply tourniquet at base of finger
      2. Identify point of maximal tenderness and swelling
         1. Make 5-10 mm incision using method below
      3. No specific point of tenderness
         1. Make straight single volar or high lateral incision
            1. Start incision 3-5 mm distal to DIP joint
            2. Keep lateral incision within 5 mm of nail border
            3. Continue incision distally to distal phalanx tip
            4. Thumb and pinky finger: Incise radial side
            5. Index, long and ring fingers: Incise ulnar side
         2. Avoid incision methods with higher risk of scar
            1. Transverse palmar incision
            2. J-shaped incision
            3. Fish mouth incision
      4. Wound exploration
         1. Gently open subcutaneous tissue with hemostat
         2. Irrigate wound
         3. Pack with sterile gauze for 48 hours
   5. Complications
      1. Painful neuroma
      2. Finger pad instability
      3. Scarring
9. Follow-up care
   1. Splint and elevate for 48 hours
   2. Saline soaks twice daily
   3. Maintain range of motion
   4. Anticipate healing in 2 weeks
10. References
    1. Clark (2003) Am Fam Physician 68:2167-76