Morton's Neuroma: This condition is characterized by sharp, intermittent pain in the toes, often at the base, due to compression or irritation of the intermetatarsal nerves. The absence of swelling or bruising and the location of the pain at the base of the fifth toe make this a plausible diagnosis.

Gout: Although gout typically presents with acute onset of intense pain, swelling, and redness, it can sometimes manifest with less severe symptoms, especially in its early stages. The sharp pain and lack of known injury could suggest gout, especially if the patient has risk factors such as diet or family history.
Bursitis: Inflammation of the bursae around the joints can cause sharp pain, especially with movement or pressure. The base of the fifth toe has several bursae that could become inflamed, leading to pain.
Tendinitis: Inflammation of the tendons, which could be due to overuse or strain, might cause sharp pain at the base of the toe, especially with movement.

Osteomyelitis: Bone infection, although rare and less likely without a known injury or systemic symptoms, could present with localized pain. Missing this diagnosis could lead to serious complications, including destruction of the bone and spread of infection.
Deep Vein Thrombosis (DVT): While DVT typically presents with swelling, warmth, and discoloration of the leg, it's conceivable that early stages or atypical presentations could manifest with pain only. Given the potential for severe consequences if missed (pulmonary embolism), it's crucial to consider DVT.
Diabetic Neuropathy: In patients with diabetes, neuropathy can cause sharp, intermittent pains in the feet. This condition is critical to identify due to its implications for foot care and the management of diabetes.

Complex Regional Pain Syndrome (CRPS): A chronic pain condition that can follow an injury, CRPS is characterized by intense burning or aching pain in the affected limb. While rare and typically associated with more widespread symptoms, it could be considered in the differential for unexplained, severe pain.
Erythromelalgia: A disorder that causes burning pain, heat, and redness in the hands and feet, erythromelalgia could potentially cause sharp, intermittent pain if the symptoms are mild or atypical.
Neurological Disorders (e.g., Peripheral Neuropathy from other causes): Various neurological conditions can cause foot pain, including sharp, intermittent pain. These would be considered based on the patient's overall clinical picture and risk factors.

Morton's Neuroma: Diagnosis is often clinical, but ultrasound or MRI can confirm. Treatment includes wide, comfortable shoes, orthotics, and in severe cases, injection with corticosteroids or surgical intervention.
Gout: Diagnosis involves clinical presentation, serum uric acid levels, and sometimes arthrocentesis for crystal analysis. Treatment includes NSAIDs, colchicine, and urate-lowering therapy for chronic management.
Bursitis and Tendinitis: Diagnosed clinically, with ultrasound for confirmation if needed. Treatment involves rest, ice, compression, elevation (RICE), NSAIDs, and physical therapy.
Osteomyelitis: Diagnosed with blood tests, imaging (X-ray, MRI), and sometimes bone biopsy. Treatment involves antibiotics and possibly surgical debridement.
DVT: Diagnosed with D-dimer blood test and ultrasound. Treatment involves anticoagulation.
Diabetic Neuropathy: Diagnosed clinically, with nerve conduction studies if needed. Management involves tight glucose control, pain management with medications, and preventive foot care.
CRPS, Erythromelalgia, and other rare conditions: Diagnosis is based on clinical criteria and sometimes specific tests (e.g., thermoregulatory sweat test for CRPS). Treatment varies widely depending on the condition and may include medications, physical therapy, and lifestyle modifications.