Seborrheic keratoses (say "seh-buh-REE-ick
kair-uh-TOH-sus") are noncancerous (benign) skin growths that some people
develop as they age. They often appear on the back or chest, but they can occur
on any part of the body. Seborrheic keratoses grow slowly, in groups or singly.
They are usually easy for a doctor to diagnose. You may not like how they look,
but they aren't harmful.1
How can I identify a seborrheic keratosis?
How
seborrheic keratoses look can vary widely. They may be pale white to brown or
black. The most common texture is rough, with a bumpy, grainy surface that
crumbles easily.2 But they also may be smooth and
waxy. They usually look like they've been stuck onto the skin. Some are tiny,
and others grow larger than
3 cm (1.2 in.) in
diameter.2
Doctors don't
know what causes seborrheic keratoses. But research has found:3
They tend to run in
families.
They seem to be related to sun exposure.
They are not contagious, so you cannot spread them to
someone else. There is no known way to prevent them.
Seborrheic
keratoses are common in middle-aged people, but they can appear as early as the
teen years.3 Some women notice that they get them
during pregnancy or after taking
estrogen. Children seldom have these skin growths.
Are there risks related to seborrheic keratoses?
A
diagnosed seborrheic keratosis is nothing to worry about. But seborrheic
keratoses sometimes are mistaken for cancerous (malignant) skin growths. Or
cancerous growths may blend in with seborrheic keratoses. If you have a skin
growth that appears to be a seborrheic keratosis, ask your doctor to examine
it. If you have a dark skin growth or a group of growths that develop rapidly,
make an appointment to have them checked now.
How is it treated?
Seborrheic keratoses do not
need to be treated. But if a seborrheic keratosis is easily irritated or
painful or if the way it looks bothers you, you can have it removed.
Seborrheic keratoses are common skin growths that usually cause no symptoms. They
are benign, which means they are not cancerous. But they can itch, bleed
easily, or become red and irritated when clothing rubs them.
Seborrheic keratoses can grow on any part of the body in clusters or
singly. They occur most commonly on the back or chest. They often look like
they have been pasted onto the skin. They can be flat or raised and can vary in
appearance. Seborrheic keratoses:
Range in color from white to light tan to
black. Most are brown. Some are multicolored.
Range in size from
tiny to larger than
3 cm (1.2 in.) in
diameter.
Range in texture from waxy and smooth to velvety to dry,
rough, and bumpy.
May have dry scale, which you can easily pick
off.
Can have a surface that crumbles when picked.
Can
be dome-shaped with tiny white or black "horns" growing from the
surface.
Can be in a cluster of different-colored
growths.
Can resemble
skin tags (small, soft pieces of skin that stick out
on a thin stem).
Can swell and turn red without apparent
cause.
Slowly grow over time, and seldom go away on their
own.
The tendency to have seborrheic keratoses that grow in
clusters seems to run in families and may be passed down from parent to child.
In rare cases, a sudden growth of many seborrheic keratoses is related to
cancer elsewhere in the body.
Several
other skin conditions, such as warts and skin cancer, can look like seborrheic
keratosis.
Exams and Tests
Your doctor can diagnose most
seborrheic keratoses by doing a visual exam. He or she
will look for the common appearance of a rough and bumpy surface.2 You may need a
skin biopsy to rule out cancer if you have growths
that:
Itch or bleed.
Become inflamed and
red.
Are dark brown to black.
Treatment Overview
Seborrheic keratoses do not require treatment because they are not cancerous or
otherwise damaging to your health. But if a seborrheic keratosis causes pain
and discomfort or causes you concern about how it looks, your doctor can remove
it.
Your treatment choices are:
Cryotherapy, the use of extreme cold.
It works well for flat or slightly raised growths, but it may not work well for
thicker growths.
Curettage, in which
your doctor uses a spoon-shaped instrument (curette) to remove the growth.
Regrowth is common after curettage alone.
Electrocautery (or
electrodesiccation), which sends a low-voltage electrical charge through the
tip of a needle to burn off a growth. This treatment is sometimes combined with
curettage.
Surgical excision, the removal of the growth with a
scalpel after your doctor injects a local anesthetic.
Laser, an intense beam of light that burns and
destroys the growth.
What To Think About
Your doctor can tell you which
treatments are best for your seborrheic keratosis, based on its type, size, and
location. Be aware that your health insurance may view seborrheic keratosis
removal as an elective procedure.
After a seborrheic keratosis is
removed, the wound may be painful for a few days. Your doctor will tell you how
to care for the wound as it heals. You may need to clean the area regularly and
apply antibiotic ointment to prevent infection.
Removal of
seborrheic keratoses is usually done in a way to minimize scarring.
Cryotherapy, electrocautery, or laser treatment may cause permanent lightening
of darker skin. Factors that may slow healing include advanced age, sun damage,
and tobacco smoking.
Home Treatment
If clothing and daily activities
irritate a
seborrheic keratosis, you can cover it with an
adhesive bandage to prevent rubbing and bleeding.
If you have had
a seborrheic keratosis removed, your doctor will tell you how to care for the
wound as it heals. You may need to clean the area regularly and apply
antibiotic ointment to prevent infection.
The American Academy of Dermatology provides information about the
care of skin, hair, and nails. You can find a dermatologist in your area by
calling 1-888-462-DERM (1-888-462-3376).
Motley RJ (2006). Seborrheic keratosis. In MG Lebwohl
et al., eds., Treatment of Skin Disease, 2nd ed., pp.
609-610. London: Mosby Elsevier.
Habif TP (2004). Seborrheic keratoses. In TP Habif,
ed., Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 4th ed., pp. 698-705. Edinburgh: Mosby.
Thomas VC, et al. (2008). Seborrheic keratosis section
of benign epithelial tumors, hamartomas, and hyperplasias. In K Wolff et al.,
eds., Fitzpatrick's Dermatology in General Medicine, 7th
ed., vol. 1, pp. 1054-1056. New York: McGraw-Hill Medical.
Other Works Consulted
Habif TP, et al. (2005). Seborrheic keratosis section
of Benign skin tumors. In Skin Disease: Diagnosis and Treatment, 2nd ed., pp. 384-393. Philadelphia: Elsevier
Mosby.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.
Motley RJ (2006). Seborrheic keratosis. In MG Lebwohl
et al., eds., Treatment of Skin Disease, 2nd ed., pp.
609-610. London: Mosby Elsevier.
Habif TP (2004). Seborrheic keratoses. In TP Habif,
ed., Clinical Dermatology: A Color Guide to Diagnosis and Therapy, 4th ed., pp. 698-705. Edinburgh: Mosby.
Thomas VC, et al. (2008). Seborrheic keratosis section
of benign epithelial tumors, hamartomas, and hyperplasias. In K Wolff et al.,
eds., Fitzpatrick's Dermatology in General Medicine, 7th
ed., vol. 1, pp. 1054-1056. New York: McGraw-Hill Medical.
