Differential Diagnosis for Left Thumb Contusion
Single Most Likely Diagnosis
- Contusion with localized neuropraxia: This is the most likely diagnosis given the symptoms of a contusion with sensory changes, which are concerning for localized nerve damage. The presentation of sensory changes without significant motor deficits or severe pain suggests a neuropraxia, which is a temporary and reversible condition.
Other Likely Diagnoses
- Distal phalanx fracture: A fracture of the distal phalanx could explain the pain and swelling associated with a contusion, and if the fracture is non-displaced, it might not be immediately apparent on physical examination. Sensory changes could be due to swelling or fracture fragments irritating nearby nerves.
- Nerve compression or neuropathy: Compression of the digital nerves could result from swelling or direct pressure on the nerves, leading to sensory changes. This could be a component of the injury or a separate issue exacerbated by the contusion.
Do Not Miss Diagnoses
- Compartment syndrome: Although less likely, compartment syndrome is a serious condition that requires immediate attention. It could occur if there is significant swelling within the closed compartments of the thumb, leading to increased pressure and potential nerve and muscle damage.
- Infection (e.g., cellulitis or abscess): Any break in the skin, even a small one, could lead to infection. Early recognition and treatment of infection are crucial to prevent serious complications.
Rare Diagnoses
- Raynaud’s phenomenon: This condition involves vasospasm of the arteries to the fingers, triggered by cold or stress, and could potentially be exacerbated by a contusion, leading to sensory changes and pain.
- Complex regional pain syndrome (CRPS): A rare condition characterized by intense burning or aching pain in the hands or feet after an injury, which could be considered if the pain is disproportionate to the injury and other diagnoses have been ruled out.