Exams and Tests
The correct diagnosis will start with a detailed history and physical exam. A directed history will help identify the likely cause as well as the correct diagnosis. People who have a localized infection will be treated differently than someone with a severe infection. Coexisting problems such as diabetes or blood vessel disorders of the arms and legs will complicate the infection and may change the degree of treatment.
- Important information that your doctor will need to know will include the following:
- How did the injury or infection start?
- When did this first occur or begin?
- Where did it occur? Home? Work? In water? In dirt? From an animal or human bite?
- Is it possible that a foreign body is in the wound?
- What have you done to care for this before seeing your doctor?
- When was your last tetanus shot?
- Any previous injuries to the area?
- Any other medical problems that you may have not mentioned?
- Specific information may help pinpoint the type of finger infection:
- Paronychia: A history of nail biting may aid the diagnosis.
- Felon: A history of a puncture wound or cut will aid the diagnosis. This would include a plant thorn. The doctor may obtain an x-ray to look for involvement of the bone or possible foreign body.
- Herpetic whitlow: A history of contact with body fluids that may contain the herpes virus will aid the diagnosis. The diagnosis can often be made from the history and the appearance of the lesions. The presence of a clear fluid from the wounds may indicate a viral infection rather than a bacterial infection. A sample of the fluid may be analyzed by a Tzank smear, which will identify certain cells, indicating a viral cause.
- Cellulitis: The doctor will need to consider other causes that may look similar such as gout, various rashes, insect sting, burns, or blood clot before the final diagnosis is made. An x-ray may be obtained to look for a foreign body or gas formation that would indicate a type of serious cellulitis.
- Flexor tenosynovitis: A history of a puncture wound or cut will aid the diagnosis. The presence of the 4 Kanavel signs is a strong diagnostic aid. A recent sexually transmitted disease may indicate a type of gonorrhea-related infection, which may resemble flexor tenosynovitis.
- Deep space infections: A history of puncture wound or other wound may aid the diagnosis. The finding of swelling between the fingers with a slow spreading of the involved fingers will help identify a collar button abscess.