Differential Diagnosis for Midfoot Pain
The patient presents with intermittent pain along the dorsum of the midfoot, worsening in the mornings, and an acute severe episode this morning. Here's a categorized differential diagnosis:
- Single most likely diagnosis
- Midfoot sprain or strain: Given the location of the pain and the absence of trauma, a midfoot sprain or strain is plausible, especially if the patient has recently increased physical activity. The intermittent nature and morning worsening could be due to inflammation or overuse.
- Other Likely diagnoses
- Stress fracture: A stress fracture in one of the midfoot bones (e.g., navicular, cuboid) could explain the pain, especially if it worsens with activity and improves with rest. The lack of trauma does not rule out a stress fracture, as these can occur from repetitive stress.
- Midfoot arthritis: Early onset arthritis, such as osteoarthritis or rheumatoid arthritis, could cause midfoot pain, stiffness (especially in the mornings), and swelling. However, the patient's age and lack of similar past episodes make this less likely.
- Tendinitis (e.g., peroneal, extensor tendons): Inflammation of the tendons around the midfoot could cause pain, especially with activity. Morning stiffness and worsening pain could be consistent with tendinitis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Osteomyelitis or septic arthritis: Although the patient denies fever or chills, and there's no mention of immunocompromised status, these infections can present subtly and would be catastrophic if missed. The acute severe pain and mild swelling could be indicative of an infectious process.
- Deep vein thrombosis (DVT): While less common in the foot, a DVT could cause severe pain, swelling, and potentially lead to a pulmonary embolism if not addressed promptly.
- Rare diagnoses
- Coalition (tarsal coalition): A congenital or acquired condition where two or more of the tarsal bones in the foot are joined by bone, cartilage, or fibrous tissue. This could cause midfoot pain, especially if it becomes symptomatic in adulthood.
- Gout or pseudogout: Although less common in the midfoot, these conditions could cause acute, severe pain and swelling, typically accompanied by systemic symptoms like fever, which are absent in this case.
- Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the feet, which could potentially cause severe pain in the midfoot area, though it's less likely given the description.