Ingrown Toenails

Updated: Apr 05, 2016
  • Author: Thomas E Benzoni, DO, MT(ASCP); Chief Editor: Trevor John Mills, MD, MPH  more...
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Ingrown toenails (unguis incarnatus) are a common toenail problem of uncertain etiology. Various causes include poorly fit (tight) footwear, infection, improperly trimmed toenails, trauma, and heredity. The great toe is the most commonly involved. [1] The lateral side is involved more commonly than the medial side. [2, 3, 4]  The ingrown nail is often diagnosed in school children, adolescents, young adults, and pregnant women. [1]  

Packing, taping, gutter treatment, and nail braces are options for relatively mild cases of ingrown toenails, whereas surgery is exclusively done by physicians, and phenolization of the lateral matrix horn is now the safest, simplest, and most commonly performed method with the lowest recurrence rate. [5, 6, 7, 8, 9, 10, 11]  Nail phenolization is indicated when partial and definitive removal of the nail plate is necessary. [7]  Chemical matricectomy using 10% sodium hydroxide has been shown to be as efficacious as phenolization. [8]

An ingrown toenail is shown in the photo below.

Appearance of typical ingrown toenail. Appearance of typical ingrown toenail.


The underlying cause of this condition is a foreign body reaction. When the nail bed is compressed from the side, the edge of the nail penetrates the cuticle. A foreign body reaction is set up by the presence of the keratinaceous nail material in the flesh of the toe.



The principal morbid condition of ingrown toenail is pain. However, it can be the initiating pathway for more serious disorders in certain patients at risk, especially those with diabetes or arterial insufficiency.

Particular attention must be paid to high-risk patients. Referral to specialty clinics for follow-up (eg, surgeon, podiatrist) is recommended for these patients.

This disorder is not found in the preambulatory stages. Rare in preteens, it is more common in teenagers, and its occurrence increases throughout life.