Treatment of Finger Felon
A felon requires surgical incision and drainage once an abscess has formed, and antibiotics are not necessary after adequate surgical excision in otherwise healthy patients. 1
Clinical Recognition
A felon presents as a tense, painful swelling of the fingertip pulp space, distinct from infections of the nail fold or surrounding structures 2. The infection involves the closed compartments of the distal digit and can rapidly spread through the flexor tendon sheath if inadequately treated 3.
Initial Assessment and Workup
Before any intervention, perform the following:
- Wound exploration with a sterile probe to assess depth, detect foreign bodies, and evaluate for bone involvement 2
- Obtain tissue samples (not superficial swabs) before initiating antibiotics for accurate pathogen identification 2
- Radiography is mandatory as initial imaging to detect fracture fragments or foreign bodies in all suspected acute hand trauma, including penetrating injuries 4
- Assess for complications including signs of arthritis, osteomyelitis, flexor tenosynovitis, or lymphangitis 1
Definitive Treatment: Surgical Drainage
The primary treatment is surgical incision and drainage 5, 1. The preferred surgical approaches are:
- Longitudinal incision in the volar space if the abscess is superficial 6
- Lateral space incision if the abscess is deep 6
- Critical caveat: Do not extend the incision past the distal interphalangeal joint space 6
- Extension to hockey stick or fish mouth incisions may be indicated only in select complicated cases 6
The success of treatment depends entirely on the completeness of surgical excision 1. Inadequate drainage is the primary cause of treatment failure 1.
Antibiotic Therapy
Antibiotics are NOT necessary after adequate surgical drainage in uncomplicated cases 1. A prospective study of 46 patients demonstrated excellent outcomes (45/46 healed without complications) following surgical excision without postoperative antibiotics 1.
When to Use Antibiotics
Reserve antibiotics for:
- At-risk patients: immunosuppressed, diabetic, or cardiac valve prosthesis recipients 1
- Complicated infections: signs of arthritis, osteomyelitis, flexor tenosynovitis, or lymphangitis 1
- Empiric coverage should target Staphylococcus aureus (including MRSA in high-risk populations) and Streptococcus species 2
Important Exception
Atypical organisms require prolonged antibiotic therapy: Mycobacterium abscessus infections (which can occur after nail salon procedures) require combined antibiotic regimens including imipenem, linezolid, tigecycline, and clarithromycin for adequate treatment 7.
Adjunctive Measures
- Elevation of the extremity is essential and should be maintained throughout treatment 5
- Remove constricting jewelry or tight clothing 5
- Update tetanus prophylaxis if vaccination status is unknown or >5 years since last booster for contaminated wounds 2
Common Pitfalls to Avoid
- Never rely on antibiotics alone once an abscess has formed - this will not replace adequate drainage 5
- Do not perform superficial swabs - obtain deep tissue samples before antibiotics 2
- Do not skip radiography - foreign bodies and fractures must be excluded 4
- Recognize that "minor" finger infections are only minor when diagnosed and treated properly - mistreatment can have long-term functional implications 5