Differential Diagnosis for Cat Bite to Hand and Finger Unable to Move

• Single Most Likely Diagnosis
  • Cat bite infection or abscess: This is the most likely diagnosis due to the high risk of infection from cat bites, especially to the hand. Cat bites can introduce bacteria like Pasteurella multocida into the wound, leading to infection, which can cause swelling, pain, and decreased mobility of the affected finger.
• Other Likely Diagnoses
  • Tendon injury or laceration: The bite could have directly injured the tendons of the hand or finger, leading to an inability to move the finger.
  • Nerve damage: The bite might have caused nerve damage, affecting the motor function of the finger.
  • Cellulitis: An infection of the skin and subcutaneous tissues, which can result from a cat bite and cause swelling and pain that limits finger movement.
• Do Not Miss Diagnoses
  • Osteomyelitis: Although less common, osteomyelitis (infection of the bone) is a serious condition that can occur after a cat bite, especially if not properly treated. It can lead to severe complications if missed.
  • Septic arthritis: If the bite introduces bacteria into a joint, it can lead to septic arthritis, a condition that requires prompt treatment to prevent permanent joint damage.
  • Tetanus: While rare in individuals with up-to-date tetanus vaccinations, tetanus infection is a potentially life-threatening condition that can be contracted through bites and cuts.
• Rare Diagnoses
  • Rabies: Although extremely rare in domestic cats in many countries, rabies is a fatal viral disease that can be transmitted through the bite of an infected animal.
  • Cat-scratch disease (Bartonellosis): Typically associated with scratches rather than bites, this condition can cause lymphadenopathy and other systemic symptoms, but it's less likely to cause localized infection leading to finger immobility.
  • Eikenella corrodens infection: This bacterium can be part of the oral flora of cats and dogs and can cause infections after bites, though it's more commonly associated with dog bites.