Differential Diagnosis for Atraumatic Posterior Right Foot/Ankle Pain
Single Most Likely Diagnosis
- Plantar Fasciitis: This condition is characterized by inflammation of the plantar fascia, leading to pain in the heel and bottom of the foot. The pain is typically worse with weight-bearing activities and improves with rest. The fact that ice helps reduce discomfort and the presence of mild numbness to toes (possibly due to compression or referred pain) supports this diagnosis.
Other Likely Diagnoses
- Achilles Tendinitis: Inflammation of the Achilles tendon can cause pain in the posterior ankle, especially with activity. The pain can be exacerbated by ambulation and may improve with ice.
- Peroneal Tendinitis: Inflammation of the peroneal tendons, which run along the posterior and lateral aspects of the ankle, can cause pain in this area, especially with activity and weight-bearing.
- Tarsal Tunnel Syndrome: Compression of the posterior tibial nerve as it travels through the tarsal tunnel can cause numbness, tingling, and pain in the foot, which may be exacerbated by activity and relieved by rest and ice.
Do Not Miss Diagnoses
- Deep Vein Thrombosis (DVT): Although less common in the absence of trauma or significant risk factors, DVT can cause leg pain and swelling. It's crucial to consider this diagnosis due to its potential for severe complications, such as pulmonary embolism.
- Osteomyelitis or Septic Arthritis: Infection of the bone or joint can cause severe pain, redness, and swelling. While these conditions are more commonly associated with trauma or systemic symptoms, they should not be overlooked due to their serious nature.
- Peripheral Artery Disease (PAD): Reduced blood flow to the lower extremities can cause pain at rest, which may be relieved by dependency or warmth. Although PAD typically presents with claudication (pain with walking that improves with rest), atypical presentations can occur.
Rare Diagnoses
- Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the feet and hands. It can be primary or secondary to other conditions.
- Complex Regional Pain Syndrome (CRPS): A chronic pain condition characterized by severe, burning pain at the site of an injury, which can be out of proportion to the severity of the initial injury. It may also involve swelling, changes in skin temperature, and sensitivity.
- Neoplastic Processes: Tumors, either benign or malignant, can cause pain and other symptoms in the foot and ankle. While rare, these should be considered in the differential diagnosis, especially if the pain is persistent and unexplained by other causes.