An ingrown toenail is caused by pressure of
the nail against the skin on the side of the nail. Prolonged
periods of pressure can cause irritation of the skin, swelling,
infection, and pain. Ingrown nails are seen mainly in the big
toes of people in industrialized nations. People in cultures
that don't wear shoes rarely get ingrown nails.
Causes of Ingrown Toenails
Improperly cutting the toenail, cutting it short
and curved, can cause the nail edges to turn in. Certain conditions
such as lung disease, advancing age, and poor circulation in the
extremities from blocked blood vessels can cause the nail to curve.
Other less common factors that can lead to ingrown nails are bone
spurs under the nail, trauma to the nail, multiple infections, and
drugs such as indinavir.
There are several factors that can lead to an ingrown toenail.
The first is an abnormality of the soft tissue on the side of
the nail. Certain rare diseases can cause a laxity of the skin,
but the most common soft tissue abnormality is that seen with
tight-fitting shoes. The shoes cause overcrowding of the toes
pushing the soft tissue against the edge of the nail. Another
common factor that can lead to ingrown toenails is nail
Appearance of Ingrown Toenails
There are three stages of ingrown toenails. In the first stage
the skin on either side of the nail is red and painful to the
touch. This is due to inflammation or irritation only - not
infection. In the second stage the skin is infected and may
bulge over the side of the nail. The affected area may ooze
clear fluid or pus. In the third stage the skin has been
infected for a prolonged time and is trying to heal itself. The
skin does this by forming granulation tissue. This is heaped up
extra red tissue that bleeds easily and migrates over the nail
Diagnosis of Ingrown Toenails
Ingrown toenails are diagnosed clinically by their appearance.
If pus is present, it may be cultured to determine the bacteria
involved, but this is not always necessary. Infections that
involve the bone or joint space may need to be ruled out with an
X-ray, but this extent of infection is rare.
Treatment of Ingrown Toenails
Ingrown toenails are treated based on the stage involved.
Toenails in stage 1 can be treated with warm soaks, a cutout
shoe, and by elevating the nail with a cotton swab. Symptoms
improve after a couple of days, but may not resolve for 2 to 3
weeks. Toenails in stage 2 can be treated with warm soaks and
oral antibiotics. Closed-toed shoes and hosiery should not be
worn for at least 1 week. If the toenail is especially painful,
a portion of the toenail may need to be removed. This is done in
the office under local anesthesia. Toenails in stage 3 need to
be treated with partial or full toenail removal. For recurrent
instances of ingrown nails, the nail bed can be ablated. This is
done by placing phenol on a cotton swab and inserting it under
the cuticle remaining after the nail has been removed. The
phenol kills the matrix cells that make the nail plate.
Diabetics and Ingrown Toenails
People with diabetes must pay close attention to their feet.
Diabetics can develop peripheral neuropathies and loose the
sensation in their feet. They are also predisposed to getting
unusual infections because of the changes in their immune
systems. Finally, diabetes can cause the toenails to thicken and
curve under leading to ingrown toenails. For all of these
reasons, people with diabetes should report any redness around
the toenails to their health care provider even if they don't
have pain. Diabetics with thickened toenails should see a
podiatrist to have their nails trimmed under antiseptic