Runner’s Nail (Subungual Hematoma): Causes, Symptoms & Treatment

Runner’s Nail is a condition that generally affects the nails of the longer toes. One of the most common presentations is a purple discoloration due to bruising of the tissue under the nail or a subungual hematoma which is the medical term for what is essentially a blood blister. In some cases part or all of the nail separates from the underlying nail bed. Pain and discomfort are not always present.

The nail has been subjected to micro-trauma secondary to sustained pressure or friction on the toe. The typical circumstances responsible for this are long distances, downhills, improper sneaker fit, and excess nail length.

Pain is most typically associated with a collection of fluid (a combination of blood and serous contents) under the nail. Most often a podiatrist can reduce the pressure by simply removing the trapped fluid. Most cases do not involve local anesthesia and in over 20 years, I have never “drilled” a hole through the nail plate. Oftentimes the sac of fluid can be easily accessed with the tip of a sterile surgical blade or the tip of a sterile needle. The affected area can then be irrigated with an antimicrobial solution.

If a portion of the nail is separated from the nail bed (lysis), it can be gently trimmed away. This prevents the nail from additional sudden traumatic lysis which can occur by just putting socks on or accidentally impacting the toe against a stable object.

When only bruising is present one can wait for the discoloration to grow out as the nail itself grows. This process can be lengthy as toenails grow an average of 1.5-1.75 mm/month.

Runner’s nail is vulnerable to fungal infection as the bond between the nail and the underlying nail bed may no longer be intact. This is an ideal opportunity for fungus to enter. Fungus thrives in warm, dark, moist areas. It is present in foot wear and can then easily migrate under a traumatized nail. Prophylactic steps can be taken to minimize this risk such as trimming away any unattached nail portions, applying a topical antifungal daily, wearing moisture wicking socks such as those made of wool, and spraying the interior of foot wear with anti-fungal sprays.

Some runners may be prone to bacterial infections. This is characterized by redness, swelling, pain, warmth and sometimes purulence. Medical attention should be sought in these cases.

Runner’s Nail can also be associated with other athletic activities such as tennis or rock climbing. Dropping a heavy object on the nail may also induce the same features.

Article written by Dr. Corinne Gehegan