Felon: Incision and Drainage

An infection or abscess of the fingertip pulp

INDICATIONS

Fluctuance of the distal pulp with pain worsened by pressure

Failure of resolution of infection after conservative therapy

CONTRAINDICATIONS

Herpetic whitlow

Infection extending proximally to distal interphalangeal (DIP) joint

Coagulopathy

General Basic Steps

Analgesia

Incision and drainage

Irrigate

Packing and dressing

Ensure follow-up

TECHNIQUE

Perform digital block under sterile setting

Make small longitudinal incision at area of maximal fluctuance

Disrupt loculations using blunt curved hemostat without disrupting the vertical septa

Irrigate wound with sterile saline under pressure

Insert a small piece of packing gauze, creating a wick to allow drainage

Apply gentle nonadhesive dressing and ensure follow-up in 24 to 48 hours to remove packing

Splint the involved finger

Ensure tetanus is updated

Encourage elevation to minimize pain and follow up with the hand surgeon

COMPLICATIONS

Digital nerve injury

Osteomyelitis

Painful neuroma (FIGURE 72.1)

Flexor tenosynovitis

Skin necrosis

Septic arthritis

Fingertip deformity

SAFETY/QUALITY TIPS

Procedural

Incisions should not be within 3 mm of the DIP joint to prevent flexion contracture and deformity

Transverse incisions can injure the neuromuscular bundle causing ischemia and anesthesia

Use of a fish-mouth incision is associated with a higher rate of complications

The longitudinal incision at the area of maximal fluctuance is associated with the lowest rate of complications

Cognitive

Provide antistaphylococcal/antistreptococcal antibiotic coverage if felon is associated with overlying cellulitis; especially in patients with underlying diabetes or other immunocompromised condition

Incision is contraindicated in the setting of herpetic whitlow as it may result in delayed resolution, viremia, or bacterial superinfection. Herpetic whitlow features vesicles that coalesce with pus, mimicking a felon or paronychia; look for and ask about vesicles. Whitlow is more common in health care workers (exposed to the saliva of herpes-infected patients). The pulp of the distal phalanx should be soft with whitlow, tense with a felon.