Ingrown nail refers to the condition in which the edge of a nail cuts into the adjacent skin fold, causing pain, redness, and swelling.
Ingrown nail (onychocryptosis) occurs when the nail plate (the horny covering) grows into and cuts the skin alongside the nail (lateral nail fold). Ingrown toenails make up 3–5% of all foot problems. Most cases of ingrown nail occur in men between the ages of 10–30 years. In this age group, males are affected twice as often as females. In older adults, the incidence is equal. There are three major types of ingrown nail: subcutaneous ingrown nail, in which the nail grows under the skin; over-curvature of the nail plate; and hypertrophy (overgrowth) of the lateral nail fold.
Ingrown nails occur most often on the big toe. Penetration of the nail into the skin causes inflammation (swelling and redness). Infection by bacteria or fungi may follow. Severe infection may lead to abscess formation, characterized by an oozing pus-filled blister. Small translucent red bumps called granulation tissue may develop along the lateral nail fold.
Causes & symptoms
Ingrown nails are most commonly caused by incorrect cutting of the nails and wearing poorly-fitting shoes. Other causes of ingrown nail include:
- abnormally long toes
- overcurvature of the nail
- excessive sweating
- shoes that put pressure on the toes (pointed-toe, high-heeled)
- poor foot hygiene
- high lateral nail folds
- discrepancy between the widths of the nail and nail bed
- improper alignment of the large toenail
- repeated trauma to the large toe
The symptoms of ingrown nail include swelling, redness, and pain in the lateral nail fold. Increased swelling, pus drainage, and ulceration (tissue destruction) can occur as the condition progresses. Advanced onychocryptosis is characterized by long-term swelling, the formation of granulation tissue, and lateral fold overgrowth.
Ingrown nail is easily diagnosed in a physical examination done by a family physician, a podiatrist (foot specialist), or a dermatologist (skin specialist).
Because of the possibility of serious complications, a physician should be consulted for treatment of severe and/or infected ingrown nails. Alternative treatments for treating ingrown nail include:
- Ayurveda. Ayurvedic principles state that persons whose constitutions are dominated by vata and kapha have stronger nails and are prone to ingrown nails. Ingrown nails are treated with warm water soaks followed by application of a solution of equal parts tea tree and neem oils under the nails.
- Herbal therapy. When an ingrown nail is forming, the toe should be soaked for 15–30 minutes in five drops each of hypericum and calendula tinctures diluted in 1/2 pint of warm water. Afterward, the toe should be wrapped in linen, placing it between the fold and the nail.
- Homeopathy. Preparations of Hepar sulph. or Silica in 6c potency may be taken every 12 hours for two weeks, to reduce the inflammation around the nail.
- Hydrotherapy. To treat ingrown nail, the patient should soak the foot in hot, soapy water for 20 minutes, trim the nail square, wrap the toe in a hot compress, and cover it with a dry cloth overnight. In the morning, the patient should trim the nail into a U shape and place a bit of cotton between the nail and the fold. The cotton should be kept in place until the nail grows out.
- Massage. If an ingrown nail is developing, the patient should gently push the skin away from the nail. Repeated massage of the overgrown lateral nail folds can reduce pain and separate the fold away from the nail.
Nonsurgical methods of treating ingrown nails focus on eliminating infection with medications and separating the ingrown nail from the lateral nail fold. Whenever possible, the offending nail is clipped, and the patient is instructed to soak the foot in water containing Epsom salts and povidone-iodine thrice daily. Procedures used to separate the nail from the fold include inserting a piece of fabric (moistened with antiseptics), plastic, or metal between the nail and the fold until the nail grows out. Cryotherapy, in which the affected nail fold is frozen with liquid nitrogen, is also used. Cauterization (destruction of tissue using heat) may be performed to eliminate granulation tissue. A metal brace may be worn on the toe for several months to flatten overcurvature.
In cases of severe ingrown nail or ineffective nonsurgical treatment, part or all of the nail is surgically removed. Most commonly, only a portion of the nail is removed. Ingrown nail recurs in 60%–80% of the patients. If nail regrowth is expected to cause a recurrence of ingrown nail, then the nail matrix (where nail growth occurs) is destroyed, which prevents nail regrowth. In most cases, only local anesthesia is needed for surgical treatment.
Although natural remedies can be effective in healing minor ingrown nails, prevention is the best solution. Many cases of ingrown nail require surgical treatment.
Complications of ingrown toenail include infection, osteomyelitis (infection of the bone), and gangrene (tissue death). The elderly are at increased risk of complications because of decreased sensation resulting from such conditions as diabetes, heart disease, or arteriosclerosis (hardening of the arteries).
Ingrown nails may be prevented by:
- clipping nails straight across
- leaving the nail edge slightly longer than the end of the toe
- not trimming the sides of nails
- wearing shoes with ample toe space
- not pulling or tearing at the toenails
Nails: Therapy, Diagnosis, Surgery, edited by Richard K. Scher et al. Philadelphia: W. B. Saunders Company, 1997.
Ikard, Robert W. "Onychocryptosis." Journal of the American College of Surgeons, 187 (July 1998): 96-102.