Nail trauma is a common occurrence that is usually caused by crushing or dropping something on the toe. Other causes for trauma include pressure arising from ill-fitting footwear or repetitive micro injuries caused by excessive use or abnormal biomechanics.
Nail trauma varies in severity but frequently leads to a dark discolouration under the nail. This is known as subungual hematoma, and it is caused by blood pooling under the nail. More severe cases can lead to splitting of the nail or the nail detaching from the nail bed. In the most extreme cases, the bone of the toe may also have been fractured.
Who is at risk?
As this condition is often a result of an accident, it affects both men and women of all ages. However, there are certain groups that may experience nail trauma more often.
Those who run intensively may find some of their toenails bleeding, blistering or turning black. This is caused by the repetitive microtrauma of the top of their shoe rubbing against the toe or the toe bumping against the toe box of the shoe while running.
Those wearing ill-fitting shoes
Ill-fitting shoes are likely to inflict microtrauma on the foot. Overly tight shoes may squeeze the toes, while shoes that are loose fitting may have an overly large toe box that allows the toes to bump against the shoe repeatedly, causing trauma over time.
If the nail is left untreated or not managed properly, an opening within the nail can act as a portal for infection. Bacterial, fungal or viral infections may begin to thrive within the damaged nail and can even spread to other nails or the skin if not treated quickly. If such complications develop, full healing and recovery will take much longer and there will also be a greater impact on the overall health of the patient.
Long-term effects of untreated nail trauma can include abnormal nail growth, ingrown toenails, unsightly nail deformities or other conditions. This usually happens when the nail matrix (where cells are produced to make the nail plate) is also damaged.
Visually similar complex complications
While uncommon among Singaporeans, certain types of skin cancer (melanoma) can look like nail trauma, presenting as a discolouration under the nail. This discolouration will gradually appear over time and is often painless. The pattern for subungual melanoma is usually distinctive, forming as a vertical brown or black discolouration stretching from the base of the nail to the tip.
If your nails have developed a pattern of discolouration without any cause, you should consult a podiatrist immediately. Subungual melanomas are often diagnosed at a later stage as the foot is hard to see and less frequently checked, leading to poorer survival rates among patients.1
A thorough examination is necessary to determine the extent of the damage as the treatment plan will depend on the severity of the injury. Mild cases can be resolved by nail or wound care which involves relieving the pressure by draining the blood or pus that is trapped under the nail plate. After the procedure is completed, the toe should be closely monitored to ensure that the area does not become infected.
For those patients whose trauma is caused by a biomechanical issue, fully customised insoles are necessary in order to address these issues. This will prevent further occurrence of the microtrauma and allow the existing injury to heal. If left untreated, the trauma is likely to worsen, reducing the treatment options available. At this point, surgical intervention may be required to treat this condition.