Differential Diagnosis for Sharp Pain in the Feet

The patient presents with sharp pain in the back of his feet, specifically in the toes of the left foot and the heel of the right foot, which started a month ago. Here is a differential diagnosis organized into categories:

• Single Most Likely Diagnosis
  • Plantar fasciitis: This condition is characterized by inflammation of the plantar fascia, leading to sharp pain in the heel, often described as walking on glass. The pain in the toes of the left foot could be due to a related condition or a different issue altogether, but the description of the pain in the right heel is classic for plantar fasciitis.
• Other Likely Diagnoses
  • Morton's neuroma: This condition involves a thickening of the tissue around the nerves leading to the toes, causing sharp pain in the ball of the foot or toes, which could explain the pain in the left foot.
  • Metatarsalgia: This is a general term for pain in the ball of the foot, which could be due to various reasons including poor footwear, overuse, or abnormalities in the way the foot functions.
  • Tendinitis: Inflammation of the tendons in the foot could cause sharp pains, especially if the patient has recently increased his activity level or has poor foot mechanics.
• Do Not Miss Diagnoses
  • Peripheral artery disease (PAD): Although less likely given the patient's age and the nature of the pain, PAD could cause pain in the feet during walking due to inadequate blood flow. Missing this diagnosis could lead to serious complications, including gangrene and amputation.
  • Diabetic neuropathy: If the patient has undiagnosed diabetes, neuropathy could cause sharp pains or burning sensations in the feet. Early diagnosis and treatment of diabetes can prevent long-term complications.
  • Deep vein thrombosis (DVT): Although the pain description does not classically suggest DVT, it is a condition that should not be missed due to its potential for severe consequences, including pulmonary embolism.
• Rare Diagnoses
  • Tarsal tunnel syndrome: This is a condition that is similar to carpal tunnel syndrome but affects the nerves in the foot, causing pain, numbness, and tingling.
  • Stress fractures: Small cracks in the bones of the foot could cause sharp pains, especially with activity. This would be more likely if the patient has recently increased his physical activity.
  • Gout or pseudogout: These conditions involve the deposition of crystals within the joints, leading to sudden, severe pain, often in the big toe but potentially in other areas of the foot as well.