Felon Definition
A felon is an abscess of the distal pulp (fingertip pad) that develops in the closed compartment of the volar fat pad of the distal phalanx. 1, 2
Anatomical Characteristics
- The infection occurs specifically in the pulp space of the fingertip, which is a closed compartment bounded by fibrous septa that connect the skin to the periosteum of the distal phalanx 2, 3
- These fibrous septa create multiple small compartments that limit swelling but allow pressure to build rapidly, potentially causing digital compartment syndrome 3, 4
- The confined space means that even small amounts of pus accumulation can generate significant pressure, leading to severe pain and potential complications 3
Clinical Significance
- Felons represent one of the most common hand infections seen in clinical practice 3
- The infection is typically precipitated by localized trauma to the fingertip, allowing bacterial entry into the pulp space 2
- If left untreated or inadequately managed, the infection can spread through destroyed septa into adjacent structures including the flexor tendon sheath or bone (osteomyelitis) 1, 3
- The high pressure within the closed compartment can compromise vascular supply, leading to tissue necrosis of the distal phalanx 1
Key Distinguishing Features
- A felon is anatomically distinct from a paronychia, which is an infection of the epidermis bordering the nail (proximal or lateral nail folds) rather than the pulp space 2, 3
- The location is specifically palmar/volar on the fingertip, not dorsal 3
- Patients typically present with extreme pain due to the compartmentalized nature of the infection and resulting pressure buildup 3