Fingernail and Toenail Injuries
A fingernail can be torn off when it catches on something. For example, you're falling forward into brush, holding your ungloved fingers out in front of you as you try to catch yourself. Sometimes the avulsion results from a direct blow, such as smashing a fingertip between the handlebars and a tree.
A toenail or fingernail that's knocked loose is called a nail avulsion. Unless there's a cut or fracture, this injury can be managed at home -- as long as you're sure there's no underlying fracture or a tear in the nail bed.
This fingernail ripped loose as the biker fell into a dogwood bush. Note that the base of the fingernail is lying ON TOP of the cuticle skin.
The exposed tissue can be quite sensitive. (Good protection is needed.) Infection can result if the area isn't kept clean.
See the doctor if:
there's a cut over the nail bed
there's severe pain
the finger or toe is crooked
If the nail is outside the nail sulcus (the hollow at the base of the nail from which it grows) but is still attached, remove it. A nail that's loose but still in the nail sulcus can be plastered back down IF there's NO contamination under the nail. Clean away blood and debris. Apply antibiotic ointment and a padded dressing.
A bit of superficial skin may be holding the nail. If it's thin, like the top of a blister, you can snip it with small scissors or (biker method) just grab the nail and twist it free.
Change the dressing daily. Stay away from water for 2 days. As the area becomes less sensitive, you can switch to a small dressing, such as a fingertip bandage. When the nail bed is dry and no longer sensitive to touch, you can stop bandaging. A new nail takes from 2 months (finger) to 6 months (toenail) to grow back.
See the doctor if there's increasing swelling, spreading redness, increasing pain, or increasing drainage from the nail bed. See section on infection.
While you're putting the bikes on the rooftop rack, one of them gets away. You duck, but the frame of the bike smacks your finger where you're holding onto the bar. Your fingernail throbs. It turns red, then black.
A subungual hematoma is a collection of blood and fluid under the fingernail. It's usually the result of smashing your fingertip between two hard objects. The pressure of the blood makes the fingertip uncomfortable.
If there are signs of other injuries such as a cut, swelling, limitation of motion, etc, you should see the doctor.
Draining the hematoma will relieve a lot of the pain. If the blood reaches the end of the fingernail, it's simple to let the blood out by separating the nail from the skin. Look carefully at the underside of the end of the fingernail (pull the soft part of the fingertip slightly downward if necessary). If you can see a dark line there between the nail and the pink skin, that's where you want to "operate." Clean the skin under the end of the fingernail with alcohol, peroxide, benzalkonium chloride, or Betadine. Take an extremely sharp sterile object (a pointy scalpel is ideal, but the corner of a razor blade or an injecting needle can do the job), and puncture the darkened skin right where it joins the fingernail. The blood should squirt out. Press gently on the fingernail to complete the job. Put a dressing over the nail and fingertip.
If the blood is only under the upstream half of the fingernail, you have a bigger problem. Creating a hole in the fingernail will relieve the pressure, but this isn't easy to do with the equipment in the typical household. Consider seeing your friendly local ER doctor. But if you're bound to do it yourself, you can try drilling or melting a hole in the nail. In the ER, we use a white-hot wire to quickly melt a hole in the nail. Some people use a high-speed drill or Dremmel tool. (Warning: if you try one of these techniques at home, you deserve whatever complication you create.) After draining the blood, bandage it up to keep germs from going in the hole. After a few days, plug the hold with clear nail polish or repair compound.
Keep the fingertip bandaged for a few days. Expect some residual blood color under the nail, which will slowly move forward with the growing fingernail over a couple of months. The nail may be loose in spots, so be careful about digging into sand or dirt with your fingernails. Watch for signs of infection.
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