Ingrown Nail

Ingrown nail, also known as onychocryptosis, is a common form of nail disease. It is characterised by the nail growing so that it cuts into one or both sides of the paronychium or nail bed, causing pain and sometimes infection. While it can occur in both fingernails and toenails, it is most common and problematic in the toenails, especially the big toe.

An ingrown toenail on the large toe of the right foot

Signs and Symptoms

Symptoms of an ingrown nail include pain along the margins of the nail caused by hypergranulation around the margins, worsening of pain when wearing tight footwear, and sensitivity to pressure. Bumping of an affected toe can produce sharp and excruciating pain. Signs of infection include redness, swelling, drainage of pus, and watery discharge tinged with blood. The primary symptom is swelling at the base of the nail on the ingrowing side.

Ingrown nail in hallux (big) toe

Causes

The main contributor to onychocryptosis is footwear, particularly ill-fitting shoes with inadequate toe box room and tight stockings. Other factors include damp atmospheres that soften the nail plate, genetics, trauma, and disease. Improper nail cutting can also contribute, as nails that are cut too short or at incorrect angles may grow irregularly and press into the flesh.

Simple representation of the formation of ingrown nails

Additional causes may include:

• Shoes causing bunching of toes, especially in individuals under 21
• Poor nail care, such as cutting nails too short or rounded
• Broken toenails
• Trauma to the nail plate or toe
• Bacterial infections

Prevention

To prevent ingrown nails, nails should be cut straight across, not too short, and not rounded off at the tip. Proper footwear that is not too tight or shallow is essential. Sharp square corners of nails should be avoided to prevent snagging on socks. Some nails may require more specialised cutting techniques, often performed by a podiatrist.

Management

The treatment of an ingrown toenail depends on its severity.

Conservative Treatment

Mild to moderate cases are treated with warm water and Epsom salt soaks, antibacterial ointment, and the use of dental floss. If these measures fail or if the condition is severe, surgical treatment may be necessary. Over-the-counter pain relief kits may include a sodium sulphide gel with cushions and bandages.

Nail Bracing

Nail bracing is a conservative treatment that involves lifting the sides of the toenail to gradually reshape it. There are adhesive and hooked braces, and the process usually takes around 18 months. This method is particularly useful for diabetics who need to avoid surgery.

A nail with an orthonyxic brace installed

Surgery

Surgical treatment, performed by a podiatrist, involves removing the offending part of the nail plate, known as a wedge resection. If the ingrown toenail recurs, a matrixectomy may be performed, which involves destroying the sides of the nail with chemicals or excision. Antibiotics post-procedure are generally not recommended.

A toe following wedge resection with an image of the nail removed

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Self-assessment MCQs (single best answer)

What is the medical term for an ingrown nail?

Which toe is most commonly affected by ingrown nails?

Which of the following is NOT a typical symptom of an ingrown nail?

What is the primary cause of ingrown nails?

Which preventive measure is NOT recommended for avoiding ingrown nails?

Which conservative treatment involves lifting the sides of the toenail to reshape it?

What is the surgical procedure called where part of the nail plate is removed?

Which of the following is a sign of infection in an ingrown nail?

What is the term for destroying the sides of the nail to prevent recurrence of an ingrown nail?

Which of the following is NOT a common cause of ingrown nails?