An ingrown toenail occurs when the nail grows into the skin or when the skin on one or both sides of the nail grows over that same nail. This can be quite painful and possibly lead to infection of the toe and even the underlying bone in certain cases. Ingrown toenails can be a chronic and recurring issue, with repeated episodes of pain and infection. Irritation, discomfort, redness, edema (swelling) and the presence of pus are often the symptoms.
Ingrown toenails can occur for several reasons. Excessive curvature of the nail, whether congenital or not, is a common cause. Minor repeated trauma or major trauma can also play a role. This would include pressure on the toes such as when playing a sport or when an object impacts the toe. Another frequent culprit is poor nail-cutting technique, which allows skin to grow over a section of the nail. Of course, wearing shoes that are too tight will cramp the toes and aggravate the situation.
Signs of infection include redness, pain, edema and pus on the side of the nail. There is usually presence of swelling of the adjacent skin as well. Infection develops when the ingrown toenail is kept in a moist, warm and bacteria-friendly environment (when we wear socks and shoes). As the nail penetrates the skin, it creates a gateway for pathogens from the surrounding tissues. If the ingrown toenail is left untreated, the nail can dig deeper under the skin. This leads to a much more severe infection, possibly at the bone level.