Differential Diagnosis for Unilateral Big Toe Sensation Loss

• Single most likely diagnosis
  • Morton's neuroma: This condition, characterized by a benign growth of nerve tissue, is a common cause of toe numbness or sensation loss, especially if new shoes have been worn recently, which could exacerbate the condition.
• Other Likely diagnoses
  • Poorly fitting shoes causing nerve compression: New shoes can sometimes be too tight, leading to compression of the nerves supplying the big toe, resulting in sensation loss.
  • Peripheral neuropathy: Although diabetes is considered unlikely, other causes of peripheral neuropathy (such as vitamin deficiencies, alcohol abuse, or certain medications) could still be responsible for the symptoms.
• Do Not Miss diagnoses
  • Tumor (e.g., schwannoma) compressing a nerve: Although rare, a tumor compressing a nerve could cause unilateral sensation loss in the big toe. Missing this diagnosis could have serious consequences.
  • Infection (e.g., abscess) affecting nerve function: An infection near the nerve could cause damage leading to sensation loss. Prompt diagnosis and treatment are crucial to prevent long-term damage.
• Rare diagnoses
  • Sarcoidosis: This autoimmune disease can cause neuropathy, although it would be an uncommon cause of isolated big toe sensation loss.
  • Vasculitis: Inflammation of the blood vessels can lead to nerve damage, but it is a rare cause of such specific symptoms.
  • Lyme disease: In rare cases, Lyme disease can cause neuropathy, but this would typically be accompanied by other symptoms such as a rash or systemic illness.