Differential Diagnosis for Lateral Foot Swelling and Sinus Tarsi
- Single Most Likely Diagnosis
- Sinus tarsi syndrome: This condition is characterized by pain and swelling in the lateral foot, particularly in the area of the sinus tarsi, which is a small canal on the outside of the ankle. It is often caused by overuse or repetitive strain on the foot and ankle, making it a common issue in athletes or individuals who engage in activities that involve running or jumping.
- Other Likely Diagnoses
- Peroneal tendonitis: Inflammation of the peroneal tendons, which run along the lateral aspect of the ankle, can cause swelling and pain in the area, including the sinus tarsi.
- Cuboid syndrome: This condition involves the cuboid bone in the midfoot and can cause pain and swelling on the lateral side of the foot, potentially radiating to the sinus tarsi area.
- Lateral ankle sprain: Although more commonly associated with acute trauma, chronic or recurrent lateral ankle sprains can lead to swelling and pain in the lateral foot, including the sinus tarsi.
- Do Not Miss Diagnoses
- Osteoid osteoma: A benign bone tumor that can cause severe pain, often worse at night, and swelling. Although rare, it's crucial to consider due to its potential for significant morbidity if left untreated.
- Ewing's sarcoma: A rare type of cancer that can present with swelling and pain in the foot or ankle. Early diagnosis is critical for effective treatment.
- Infection (osteomyelitis or septic arthritis): Infections in the bone or joint can cause swelling, pain, and systemic symptoms like fever. Prompt diagnosis and treatment are essential to prevent serious complications.
- Rare Diagnoses
- coalition of the subtalar joint: An abnormal connection between the bones of the subtalar joint, which can cause pain and stiffness in the foot and ankle, including the area around the sinus tarsi.
- Rheumatologic conditions (e.g., rheumatoid arthritis, psoriatic arthritis): These conditions can cause widespread joint pain and swelling, including in the foot and ankle, though they are less common causes of isolated lateral foot swelling and sinus tarsi pain.