Differential Diagnosis for Flexor Tenosynovitis vs Cellulitis of the Finger
When differentiating between flexor tenosynovitis and cellulitis of the finger, it's crucial to consider various diagnoses to ensure accurate treatment. The differential diagnoses can be categorized as follows:
- Single Most Likely Diagnosis
- Flexor tenosynovitis: This condition is characterized by inflammation of the tendon sheath in the finger, often presenting with Kanavel's signs (finger held in slight flexion, fusiform swelling, tenderness along the flexor tendon, and pain with passive extension). Given the specific symptoms and signs, flexor tenosynovitis is a strong consideration in cases where these criteria are met.
- Other Likely Diagnoses
- Cellulitis of the finger: An infection of the skin and subcutaneous tissue, cellulitis can present similarly to flexor tenosynovitis with redness, swelling, and warmth. However, it typically lacks the specific signs associated with tendon sheath involvement.
- Paronychia: An infection around the nail, paronychia can cause pain, redness, and swelling, which might be confused with the symptoms of flexor tenosynovitis or cellulitis, especially if the infection spreads.
- Felon: An abscess of the fingertip pulp, felons are extremely painful and can cause swelling and redness, potentially mimicking other conditions affecting the finger.
- Do Not Miss Diagnoses
- Necrotizing fasciitis: A severe infection that destroys tissue under the skin, including fat and the tissue covering the muscles (fascia). It requires immediate medical attention and can be fatal if not treated promptly. While less common, its potential severity makes it a critical diagnosis not to miss.
- Osteomyelitis: An infection of the bone, osteomyelitis can occur in the fingers and may present with pain, redness, and swelling, similar to other conditions. Its chronic nature and potential for severe complications make it important to consider.
- Septic arthritis: An infection in a joint, septic arthritis is a medical emergency that requires prompt treatment to prevent permanent damage. In the context of finger infections, it's crucial to consider, especially if there's significant pain or decreased range of motion in the affected joint.
- Rare Diagnoses
- Gonococcal tenosynovitis: A rare condition caused by Neisseria gonorrhoeae, it presents with symptoms similar to flexor tenosynovitis but is less common. It's an important consideration in sexually active individuals with no other clear source of infection.
- Tuberculous tenosynovitis: A form of tuberculosis that affects the tendon sheaths, it's rare in many parts of the world but should be considered in endemic areas or in individuals with a history of tuberculosis exposure.