A subungual hematoma is a collection of blood that pools in the confined space between the nail plate and the nail bed, typically resulting from a blunt force or crush injury to the finger or toe. This accumulation of blood creates intense, throbbing pain because the pressure is trapped. Relieving this pressure through a procedure called trephination can provide immediate and significant pain relief. This article provides guidance on the at-home method for safely releasing this pressure.
Assessing the Injury and When to Seek Medical Care
A subungual hematoma is clearly visible as a dark discoloration, ranging from red to black, underneath the nail plate, and is accompanied by substantial, often throbbing, pain. While the drainage procedure offers quick relief, it is not appropriate for all nail injuries and certain signs indicate an immediate need for professional medical attention.
Do not attempt to drain the hematoma at home if there is any suspicion of a fracture in the underlying bone, which may present as a visible deformity or severe pain upon moving the digit. If the injury includes a deep laceration or tear in the skin around the nail, or if the nail plate is severely disrupted, medical care is necessary for a thorough assessment and potential repair. Another important contraindication is if the blood covers more than 50% of the nail plate, as this may indicate a significant nail bed laceration that requires surgical repair.
The Home Drainage Procedure
The goal of the home drainage procedure, or trephination, is to create a small opening in the nail plate to allow the trapped blood to escape, which immediately reduces pressure and pain. Before beginning, sterilize the entire affected area and the skin surrounding the nail using an antiseptic solution like povidone-iodine or rubbing alcohol. Maintaining sterility is important to prevent introducing bacteria into the nail bed, which could lead to a serious infection.
A common method for home drainage involves using a straightened paperclip, heated until the tip glows red-hot in a flame. Hold the paperclip with a cloth to protect your fingers from the heat and apply the hot tip directly to the center of the dark hematoma on the nail surface. Do not apply any downward pressure, as the heat from the metal should melt a small hole through the nail plate without forcing the tool into the underlying tissue.
The nail plate itself contains no nerve endings, so this melting process should not cause pain, though you may need to reheat the paperclip several times for a thick nail. The moment the hole penetrates the nail, blood will begin to ooze out, and the pain should subside immediately due to the release of pressure. The procedure is complete once blood begins to drain; the objective is simply decompression, not the aggressive removal of pooled blood.
Aftercare and Signs of Complication
After the blood has drained and the pressure is relieved, gently clean the area again with an antiseptic solution. Apply an over-the-counter antibiotic ointment to the drainage site and cover the entire digit with a sterile, non-adherent dressing or adhesive bandage. To help manage residual discomfort and swelling, you can elevate the injured digit and use non-aspirin pain relievers.
For the next two to three days, you should soak the finger or toe in warm, clean, soapy water for about ten minutes, three times daily. It is normal for clear or slightly bloody fluid to continue to ooze from the small hole for up to 48 hours. If the intense, throbbing pain returns, it may indicate the hematoma has reaccumulated and a second drainage attempt may be necessary using the original hole.
You must monitor the injury site closely for any signs of infection, which is the most significant complication following this procedure. Seek immediate medical attention if you notice increasing pain, warmth, spreading redness, significant swelling, or the discharge of pus from the wound. In the long term, the damaged nail is likely to detach or shed completely as a new, healthy nail grows in from the base, a process that can take six to nine months.