Differential Diagnosis for Severe Toe Pain

The patient's presentation of severe pain and redness of the toe following a fall, with throbbing pain exacerbated by walking and mildly worsened by contact, suggests several potential diagnoses. These can be categorized as follows:

• Single Most Likely Diagnosis

  • Subungual Hematoma: This condition is characterized by a collection of blood under the nail, often due to trauma. The patient's history of a fall and the toe slipping into a pop-up drain provides a clear mechanism for such an injury. The symptoms of severe pain and redness are consistent with this diagnosis.

• Other Likely Diagnoses

  • Toenail Fracture: A fracture of the toenail or the bone underneath (distal phalanx) could also result from the described trauma, leading to pain and potentially redness if there's an associated hematoma or soft tissue injury.
  • Soft Tissue Injury (Contusion or Laceration): Direct trauma to the toe could result in a contusion or laceration of the soft tissues, which would cause pain, redness, and potentially swelling.
  • Gout: Although the patient denies increased alcohol use, gout can still be considered, especially if the patient has a history of gout or hyperuricemia. The acute onset of severe pain and redness in a single toe is consistent with a gouty attack.

• Do Not Miss Diagnoses

  • Osteomyelitis: While less likely given the acute presentation following trauma, osteomyelitis (bone infection) could present with pain and redness. It's crucial to consider this diagnosis, especially if the patient has risk factors such as diabetes or immunocompromised status, as it requires prompt antibiotic treatment.
  • Compartment Syndrome: This is a serious condition that could result from significant trauma to the foot, leading to increased pressure within the compartments of the foot. It presents with severe pain, especially on passive stretching of the toes, and could lead to serious complications if not promptly addressed.

• Rare Diagnoses

  • Toe Fracture with Complications (e.g., open fracture, fracture dislocation): While fractures are considered in the likely diagnoses, complications such as an open fracture or a fracture-dislocation are less common but could occur, especially with significant trauma.
  • Infectious Arthritis: An infection within the joint space of the toe could present with severe pain, redness, and swelling. This would be an unusual complication of a fall but could be considered, especially if there's a history of joint disease or immunocompromised status.
  • Complex Regional Pain Syndrome (CRPS): This is a rare condition characterized by chronic pain, inflammation, and hypersensitivity following an injury. It's less likely given the acute presentation but could be considered if the patient's symptoms persist or worsen over time without a clear explanation.