Onychocryptosis, commonly known as ingrown nails (unguis incarnatus) or ingrowing nails, is a common form of nail disease. It is an often painful condition in which the nail grows or cuts into one or both sides of the nail bed. While ingrown nails can occur in both the nails of the hand and feet, they occur most commonly with toenails.
Causes include:
- bad maintenance like cutting the nail too short, rounded off at the tip or peeled off at the edges (versus being cut straight across);
- ill-fitting shoes those that are too narrow or too short can cause bunching of the toes in the developmental stages of the foot (frequently in those under 21), causing the nail to curl and dig into the skin;
- trauma to the nail plate or toe which can occur by stubbing the toenail, dropping things on the toe and 'going through the end of your shoes' during sports, can cause the flesh to become injured and the nail to grow irregularly and press into the flesh; and
- predisposition abnormally shaped nail beds, history of nail fungus, nail deformities caused by diseases, and a genetic susceptibility to nail problems can mean a tendency to ingrowth.
Symptoms of an ingrown nail include pain along the margins of the nail (caused by hypergranulation that occurs around the aforementioned region), worsening of pain when wearing shoes or other tight articles, and sensitivity to pressure of any kind, even the weight of bed sheets or a duvet. Bumping of an affected toe with objects can produce sharp, even excruciating, pain as the tissue is punctured further by the ingrown nail. By the very nature of the condition, ingrown nails become easily infected unless special care is taken to treat the condition early on and keep the area as clean as possible. Signs of infection include redness and swelling of the area around the nail, drainage of pus and watery discharge tinged with blood. The main symptom is swelling at the base of the nail on whichever side (if not both sides) the ingrowing nail is forming.
