II. Definitions
- Felon (Finger Pulp Abscess, Whitlow)
- Infection of closed space of distal phalanx pulp
III. Pathophysiology
- Infection contained within compartment walled by the fibrous septae of the finger pulp
IV. Causes
- Staphyococcus aureus
- Streptococcus species
V. Mechanism: Local finger tip Puncture Wound
- Splinter
- Glass fragment
- Punctures (e.g. Finger-stick Blood Sugar testing)
VI. Symptoms
- Rapidly increasing pressure and pain at finger tip
- Thumb and index finger most commonly affected
VII. Signs
- Tense, swollen and erythematous of the finger pad (pulp)
VIII. Differential Diagnosis
IX. Imaging: Bedside Ultrasound
- May demonstrate fluid collection within pulp
X. Complications
- Osteomyelitis of distal phalanx
- Tissue necrosis of finger pulp
- Contiguous spread
- Pyogenic Flexor Tenosynovitis
- Does not typically spread to adjacent DIP joint (infection typically contained within fibrous septae)
XI. Management: Conservative measures
- Tetanus Prophylaxis
- Warm soaks
- Elevate the hand
- Antibiotics for 7 to 10 days (not typically needed for isolated abscess AFTER Incision and Drainage)
- Cephalexin (Keflex)
- Dicloxacillin
- Trimethoprim-Sulfamethoxazole
- Amoxicillin-Clavulanate (Augmentin)
- Clindamycin
XII. Management: Early Incision and Drainage
- Indications
- Clear abscess pocket identified
- No improvement after 24 hours conservative therapy
- Contraindications
- Anesthesia
- Technique
- Apply Tourniquet at base of finger
- Identify point of maximal tenderness and swelling
- Make 5-10 mm incision using method below
- No specific point of tenderness
- Make straight single volar (superficial abscess) or high lateral incision (deep abscess)
- Start incision 3-5 mm distal to DIP joint
- Keep lateral incision within 5 mm of nail border
- Continue incision distally to distal phalanx tip
- Thumb and pinky finger: Incise radial side
- Index, long and ring fingers: Incise ulnar side
- Avoid incision methods with higher risk of scar
- Transverse palmar incision
- J-shaped incision
- Fish mouth incision
- Make straight single volar (superficial abscess) or high lateral incision (deep abscess)
- Wound exploration
- Gently open subcutaneous tissue with hemostat
- Irrigate wound
- Pack with sterile gauze for 48 hours
- Complications
- Painful neuroma
- Finger pad instability
- Scarring
XIII. Follow-up care
- Splint and elevate for 48 hours
- Saline soaks twice daily
- Maintain range of motion
- Anticipate healing in 2 weeks