Felon is an abscess of the volar bulb of the finger tip that can cause pain and swelling. It occurs from penetrating trauma, such as needles or splinters. The bulb of the finger has multiple, small compartments of subcutaneous fat, separated by septa between the dorsal phalanx (bone) and the dermis. The volar distal pulp is septated, meaning it has multiple septa and multiple compartments. Staphylococcus aureus is the most common organism that causes felon. When pus occurs as part of this infection, there will be swelling, and the pressure that is built inside of the compartment will lead to multiple, little compartment syndromes. This can lead to vascular compromise and tissue necrosis. It also may lead to osteomyelitis of the bone or flexor tenosynovitis.
To treat felon, an incision and drainage should be performed. However, care needs to be taken to not violate the flexor tendon sheath or the distal interphalangeal joint. The septa should try to be broken up to decompress the infection.
If there is no foreign body in the finger, a midaxial, or “J shaped”, incision will be done and should be left open. On the other hand, if there is a foreign body present, such as a splinter or a thorn, a volar longitudinal incision will be used.
The “fish mouth incision should be avoided if possible, due to the fact that it will lead to unstable finger pulp. The double longitudinal incision should also be avoided, as it may lead to injury of the neurovascular bundle.
