Background
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. The lateral side is involved more commonly than the medial side.[1, 2, 3]
An ingrown toenail is shown in the photo below.
Appearance of typical ingrown toenail. Pathophysiology
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 then penetrates the cuticle. The presence of the keratinaceous material of the nail in the flesh of the toe sets up a foreign body reaction.
Epidemiology
Frequency
United States
The occurrence of this common disorder is poorly measured, because many instances are not brought to the attention of the medical community.
International
The frequency is unknown.
Mortality/Morbidity
The principle morbid condition of this disorder 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.
- No direct mortality for this disorder exists.
Race
No racial predilection.
Sex
No sexual predilection.
Age
This disorder is not found in the preambulatory stages. Rare in preteens, it is more common in teenagers, and its occurrence increases throughout life.
Ingrown toenails. Last updated May 2007. Familydoctor.org. Available at http://familydoctor.org/online/famdocen/home/common/skin/disorders/208.html.
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