A subungual hematoma, or blood pooling beneath the nail plate, often results from direct trauma such as a crush injury or a blow to the digit. The nail plate is rigid and adheres tightly to the nail bed tissue, creating a confined space. When blood vessels rupture, the trapped blood generates intense, throbbing pressure against the sensitive tissue. This pressure buildup is the primary source of severe pain. Treatment aims to relieve this pressure by allowing the trapped fluid to drain.
Initial Steps for Managing Pain at Home
Several non-invasive steps can help manage the discomfort caused by the pressure under the nail before seeking professional intervention. Applying a cold compress or ice pack helps constrict blood vessels (vasoconstriction), reducing blood flow to the site. This helps slow internal bleeding and minimizes further swelling, while the cold provides a temporary numbing effect. Elevating the injured hand or foot above the heart uses gravity to decrease blood pressure in the limb, further discouraging fluid accumulation. Over-the-counter pain relievers, such as acetaminophen or NSAIDs like ibuprofen, can also control the pain, though they do not affect the underlying mechanical pressure or drain the trapped blood.
Recognizing When Medical Attention is Required
While home care manages pain, certain signs indicate the injury requires immediate medical attention. A significant indicator is the size of the hematoma, especially if the dark collection of blood covers more than 50% of the nail surface. Large hematomas often suggest a substantial injury to the underlying nail bed tissue or a fracture of the distal phalanx (the small bone at the fingertip or toe). Seek care if the injury involved a crush mechanism, which increases the risk of an underlying bone fracture. Damage to surrounding structures, such as lacerations or tears in the skin around the nail, also warrants evaluation, as do signs of infection like increasing redness, swelling, warmth, or pus.
Professional Pressure Relief: The Trephination Procedure
The Procedure
The definitive method for relieving pressure is trephination, a procedure performed by a healthcare professional. This technique involves creating a small, controlled hole through the hard nail plate to allow the subungual hematoma to drain. The rapid release of the trapped blood immediately alleviates the intense, throbbing pain. The procedure is typically quick and often requires no local anesthetic, as the nail plate contains no nerve endings. Professionals use specialized, sterile tools for drainage, such as a micro-drill, a large-bore needle, or a heated electrocautery device, which melts a small hole through the plate.
Post-Procedure Care and Warnings
A strong warning must be made against attempting trephination at home using non-sterile items like a heated paper clip or pin. Draining the nail without a sterile environment carries a high risk of introducing bacteria, which can lead to a severe infection of the nail bed or bone. Improper at-home attempts can also cause severe damage to the sensitive nail bed tissue, potentially leading to permanent nail deformity or loss. After the procedure, the blood drains through the opening, and a clean dressing is applied. Patients must keep the area clean and dry, avoiding soaking the digit for a few days, and monitor the site for returning pain or infection.