What is Subungual Hematoma?
Subungual hematoma is the gathering of blood under the fingernail. Subungual hematoma is generally a result of crush or blunt type of injury to nails of the digits. The trauma causes bleeding of the nail bed or nail matrix with leads to formation of subungual hematoma. A subungual hematoma may lead to symptoms like throbbing and intense pain when the blood gets collected below the nail. Subungual hematoma(1) is not a serious condition unless there is involvement of broken bones or the nail bed is damaged along with the surrounding tissues.
Causes of Subungual Hematoma
- Subungual hematoma is generally caused by blunt trauma.
- Injury caused by slamming of the finger in a house door or car door.
- Hitting the finger with a heavy object like hammer.
- Subungual hematoma is generally caused by a blow to the distal phalanx such as crush in a door jamb.
- Subungual hematoma is often caused by crush injuries.
- Dropping a heavy object on the hand may also cause subungual hematoma.
- Repetitive pressure resulting from sports activities such as running, hiking, tennis, or soccer.
Signs and Symptoms of Subungual Hematoma
- Dark-Colored discoloration(2) under the fingernail of the affected digit.
- Pain on the nail.
- Throbbing pain under the nail.
- Quick collection of blood under the nail.
- Pressure feeling under the nail.
Treatment for Subungual Hematoma
- Subungual hematomas can mostly be treated at home and rarely needs supervision of a medical practitioner.
- Following modalities of treatment can be used in minor cases where the area of blood is less than 25% of the nail.
- Application of ice or cold therapy for 10 minutes at a time to reduce bleeding and swelling repeating it every two to three hours.
- Elevation of the hand.
- Anti-inflammatory medication such as ibuprofen for relief of pain and inflammation.
- The blood will generally drain on its own and pain and pressure relieve with the above modalities over a period of few days.
- In more severe cases where the area of blood is more than 25% of the nail, blood may need to be drained from under the nail by a medical practitioner.
- Injection of a local anesthetic is given into the finger to make it numb.
- A hole is drilled in the nail for the blood to drain through. A hole can be made by using a needle, electrocautery,(3) or a sterilized paper clip.
- The area heals on its own after drainage and usually no follow-up is required.
- In rare cases, the whole nail needs to be removed.
Investigations of Subungual Hematoma
Generally a subjective and physical examination suffices to diagnose a subungual hematoma. A thorough neurovascular examination of the digit is performed to assess for any injuries to the nerves and vessels.