Differential Diagnosis for Intermittent Swelling between First and Second Metatarsal

• Single most likely diagnosis
  • Morton's neuroma: This condition is characterized by the thickening of tissue around a nerve in the foot, commonly between the third and fourth toes but can also occur between the first and second metatarsal. It leads to pain, numbness, and swelling in the affected area, especially with pressure or tight footwear.
• Other Likely diagnoses
  • Intermetatarsal bursitis: Inflammation of the bursae between the metatarsals can cause swelling and pain, especially with activities that put pressure on the forefoot.
  • Metatarsalgia: A condition that causes pain and swelling in the ball of the foot, often due to overuse, poor foot mechanics, or ill-fitting shoes.
  • Ganglion cyst: A lump or mass that can occur on the foot, including between the metatarsals, due to a herniation of a joint or tendon sheath.
• Do Not Miss diagnoses
  • Deep vein thrombosis (DVT): Although less common in the foot, a DVT could potentially cause swelling in the area between the metatarsals if it involves the deep veins of the foot. This is a medical emergency.
  • Infection (cellulitis or abscess): Bacterial infections can cause swelling, redness, and pain in any part of the body, including between the metatarsals. Prompt treatment is necessary to prevent serious complications.
  • Tumor: Although rare, a soft tissue tumor (benign or malignant) could present as swelling between the metatarsals.
• Rare diagnoses
  • Freiberg's disease: A rare condition that affects the metatarsal bones, causing pain and swelling, typically in the second metatarsal.
  • Kohler's disease: A rare bone disorder causing pain and swelling in the foot, usually affecting the navicular bone but could potentially affect other areas.
  • Gout or pseudogout: These are forms of arthritis that can cause sudden, severe attacks of pain and swelling, often in the joints of the foot, including potentially between the metatarsals.