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. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Traumatic injury (e.g., fracture, contusion, or soft tissue injury): The mechanism of injury, where the toe slipped into a pop-up drain, directly suggests a traumatic cause for the pain and redness. The location and nature of the pain are consistent with an acute injury.

• Other Likely Diagnoses

  • Cellulitis: Given the redness and the potential for skin breach during the injury, cellulitis is a plausible diagnosis. The pain and exacerbation by contact could be consistent with an infectious process.
  • Gout: Although less likely given the acute traumatic onset, gout cannot be entirely ruled out without further investigation. Gout can present with severe pain, redness, and swelling, typically affecting the first metatarsophalangeal joint. However, the direct trauma to the toe might have triggered a gout attack in a predisposed individual.
  • Osteoarthritis or other degenerative conditions: Pre-existing conditions could be exacerbated by the trauma, leading to increased pain.

• Do Not Miss Diagnoses

  • Osteomyelitis: Although less common, an infection of the bone could occur, especially if the skin was broken during the injury. This condition requires prompt diagnosis and treatment to prevent serious complications.
  • Compartment syndrome: This is a medical emergency that could occur after a traumatic injury, characterized by increased pressure within a muscle compartment, leading to nerve and muscle damage. The severe pain, especially on walking, could be a clue, although other signs like pallor, poikilothermia, paresthesia, and paralysis (the 5 Ps) would also be expected.
  • Septic arthritis: If the joint was penetrated during the injury, introducing bacteria into the joint space, septic arthritis could occur. This condition is a medical emergency requiring immediate attention.

• Rare Diagnoses

  • Pseudogout (Calcium Pyrophosphate Deposition Disease, CPPD): Similar to gout, pseudogout can cause acute, severe joint pain and could potentially be triggered by trauma. However, it is less common than gout and typically affects different joints.
  • Neuroma: A traumatic neuroma could form after nerve damage during the injury, leading to chronic pain. However, this would be a later complication rather than an immediate diagnosis.
  • Complex regional pain syndrome (CRPS): A rare condition characterized by chronic pain, inflammation, and hypersensitivity after an injury. The presentation would typically be more complex and involve additional symptoms beyond pain and redness.