Morton's Neuroma: This condition is characterized by a sharp, intermittent pain in the foot, typically between the third and fourth metatarsals, but can also occur between the second and third metatarsals. It is caused by compression or irritation of the intermetatarsal nerve.

Intermetatarsal Bursitis: Inflammation of the bursae between the metatarsals can cause sharp pain, especially when walking or putting pressure on the foot.
Metatarsalgia: A general term for pain in the metatarsal area, which can be caused by various factors, including poor foot mechanics, overuse, or ill-fitting shoes.
Stress Fracture: Although the patient reports no injury, a stress fracture in one of the metatarsals could cause intermittent sharp pain, especially with activity.

Deep Vein Thrombosis (DVT): While less common, DVT can cause pain in the foot or leg, and it is crucial to consider this diagnosis due to its potential for serious complications, such as pulmonary embolism.
Osteoid Osteoma: A benign bone tumor that can cause severe, intermittent pain, typically at night, which is relieved by nonsteroidal anti-inflammatory drugs (NSAIDs).
Infection or Abscess: An infection in the foot, including between the metatarsals, can cause severe pain and requires prompt treatment to prevent serious complications.

Tarsal Tunnel Syndrome: Compression of the posterior tibial nerve as it travels through the tarsal tunnel can cause pain, numbness, and tingling in the foot, including the area between the metatarsals.
Freiberg's Disease: A rare condition characterized by avascular necrosis of the metatarsal head, which can cause pain in the foot, especially with weight-bearing activities.
Gout or Pseudogout: Although these conditions more commonly affect the big toe, they can cause acute, severe pain in other parts of the foot, including between the metatarsals.