Differential Diagnosis for Left Foot Dorsal Pain and Plantar Sharp Pain
Single Most Likely Diagnosis
- Morton's Neuroma: This condition is characterized by pain in the ball of the foot, typically between the third and fourth toes, which aligns with the area over the mid 3rd metatarsal. The sharp pain during weightbearing, especially plantarly, is consistent with this diagnosis. Although ultrasound may not always detect Morton's neuroma, clinical presentation is key to diagnosis.
Other Likely Diagnoses
- Stress Fracture: A stress fracture of the metatarsal bone could cause dorsal pain and sharp pain during weightbearing. The fact that nothing was seen on ultrasound does not rule out a stress fracture, as early stages might not be visible, and sometimes, a bone scan or MRI is needed for diagnosis.
- Metatarsalgia: This condition involves pain and inflammation in the ball of the foot, which could be due to various factors including poor foot mechanics, overuse, or footwear issues. It can cause both dorsal and plantar pain, especially during weightbearing activities.
- Capsulitis of the Metatarsophalangeal Joint: Inflammation of the joint capsule of the toe joints can cause pain on the dorsal and plantar aspects of the foot, particularly during weightbearing.
Do Not Miss Diagnoses
- Osteoid Osteoma: A small, benign bone tumor that can cause severe pain, often worse at night and relieved by NSAIDs. It might not be visible on ultrasound, requiring an MRI or CT scan for diagnosis.
- Erythromelalgia: A disorder that causes burning pain, heat, and redness in the hands and feet, which could potentially cause sharp pain during weightbearing.
- Complex Regional Pain Syndrome (CRPS): A condition characterized by chronic pain, inflammation, and hypersensitivity after an injury or trauma, which could present with sharp pain and other systemic symptoms.
Rare Diagnoses
- Freiberg's Disease: A rare condition that affects the metatarsal bones, causing pain and limited motion, typically in adolescents.
- Kohler's Disease: A rare bone disorder causing pain and swelling in the foot, usually affecting children.
- Gout or Pseudogout: Although more common in other areas, these conditions could potentially cause acute, severe pain in the foot, including the area over the metatarsals.