What you’ll see. Clinical signs and symptoms include pain in the pulp of the finger with tenderness and swelling. Bacteria are usually introduced into fingertip space (fat pad) by a penetrating object. Some reported cases have involved individuals with diabetes who regularly check their blood sugar (FIGURE 2).9 A defining characteristic is that the infection usually does not extend past the interphalangeal joint. Radiologic evaluation may be necessary to detect the presence of foreign bodies or to assess bone involvement (osteomyelitis of the distal phalanx).10 The differential diagnosis includes paronychia, in which the infection starts in the nail area and pain is not as intense as in a felon infection.11
How it’s treated. Surgical treatment of felon is controversial. There is no doubt that pus should be drained; how the incision is best performed, however, has been debated.12 Before surgical debridement, obtain a sample of pus for Gram stain and for cultures of aerobic and anaerobic organisms, acid-fast bacilli (AFB), and fungi (SOR: A).13,14 Several surgical techniques and their pitfalls are described in the literature.
Lateral and tip incisions may help avoid painful scars. However, multiple reports of this procedure describe injury to neurovascular bundles, leading to ischemia and anesthesia.12The “fish-mouth” incision and the “hockey stick” or “J” incision, as well as the transverse palmar incision, are no longer recommended due to painful sequelae, sensorial alterations, and risk of cutting the digital nerves.15 The preferred surgical procedure at this time is to make a very short incision over the area of maximum tenderness, then open and drain the abscess. Avoid placing packing in the affected area. Post-surgical management includes elevation, immobilization with an appropriate splint, and application of compresses until the wound has healed.12,15,16
Since Staphylococcus aureus and Streptococcus sp are the most common bacteria causing felon, start empiric treatment with an antistaphylococcal penicillin, a first-generation cephalosporin, or clindamycin. Once a microbe has been isolated, treatment can be tailored as needed. Treatment may take up to 10 to 14 days and depends on the location and resolution of symptoms.13 Assess tetanus status and give prophylaxis as needed (SOR: A).17
Acute pyogenic flexor tenosynovitis
FTS is an aggressive closed-space bacterial infection that involves the flexor tendon synovial sheath. FTS accounts for up to 10% of acute hand infections and requires prompt medical attention with wound lavage, surgical management, and antimicrobial therapy to minimize serious consequences to the digit.18
