Differential Diagnosis for Achilles Pain
Single most likely diagnosis
- Achilles Tendinitis: This is the most likely diagnosis given the location of the pain and the exacerbation with dorsiflexion. Achilles tendinitis is common in obese individuals due to increased stress on the tendon, and the lack of response to Aleve (naproxen) does not rule out this diagnosis as it may require more specific treatment such as physical therapy, orthotics, or other anti-inflammatory measures.
Other Likely diagnoses
- Achilles Tendinosis: Similar to tendinitis but involves chronic degeneration of the tendon without inflammation. It's a common condition in individuals with repetitive strain on the Achilles tendon and can coexist with tendinitis.
- Insertional Achilles Tendinitis: Specifically involves the insertion of the Achilles tendon onto the calcaneus. Symptoms can be similar to Achilles tendinitis but are more localized to the heel.
- Haglund's Deformity: A bony enlargement at the back of the heel that can irritate the Achilles tendon, leading to pain and swelling. It's more common in individuals who wear rigid shoes that press on the back of the heel.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Rupture of the Achilles Tendon: Although less likely if the patient is still able to walk and bear weight, a rupture is a medical emergency that requires prompt surgical intervention to avoid long-term disability.
- Deep Vein Thrombosis (DVT): Can present with calf pain and swelling, which might be mistaken for Achilles tendon issues. Given the patient's obesity, which is a risk factor for DVT, it's crucial not to miss this potentially life-threatening condition.
- Infection (e.g., Cellulitis or Abscess): While less common, an infection in the soft tissues around the Achilles tendon could present with pain, swelling, and redness. This would require urgent antibiotic treatment.
Rare diagnoses
- Seronegative Spondyloarthropathies (e.g., Ankylosing Spondylitis, Psoriatic Arthritis): These conditions can cause enthesitis, which is inflammation at the sites where tendons or ligaments insert into the bone, including the Achilles tendon.
- Gout or Pseudogout: Although more commonly associated with joint pain, these conditions can rarely cause tendon pain and should be considered, especially if the patient has a history of these diseases.
- Tumor or Cyst (e.g., Achilles tendon xanthoma, ganglion cyst): Rarely, a tumor or cyst can cause pain and swelling in the area of the Achilles tendon.