Felon - Nail and Distal Digit
Patients typically present with acute onset of pain, erythema, and edema at the distal fingertip pulp or pad. The distal interphalangeal (DIP) joint is the most proximal point of edema spread in felon. Containment of the abscess within the compartment can lead to high pressures at the fingertip and possible visible sinus formation. If blood flow is compromised, skin and pulp necrosis may ensue. Other complications include osteoarthritis, tenosynovitis, and septic arthritis.
Risk factors include any immunocompromised state, diabetes mellitus, and intravenous (IV) drug use, as well as work environments with increased risk of finger trauma. Immunocompromised patients have an increased risk of developing osteomyelitis. In addition, gram-negative organisms may be causative agents.
L03.019 – Cellulitis of unspecified finger
32021005 – Felon
Differential Diagnosis & Pitfalls
- Paronychia – symptoms typically at the base of the nail; can progress to felon
- Herpetic whitlow – may start with small, clear vesicles; also associated with oral and genital herpes infection
- Cellulitis – can lead to felon
- Crystalline deposition disease
- Rheumatoid arthritis
- Spider bite
- Lobular capillary hemangioma (pyogenic granuloma)
- Pyogenic flexor tenosynovitis – symptoms are on flexor surface
- Osteomyelitis – in immunocompromised patients, consider an x-ray to rule out