What is seborrheic keratosis and how can it be treated?

Seborrheic keratosis is a lesion of the skin whose impact, in most cases, is only aesthetic. It looks like a skin growth ranging in color from white to brown to even black. Usually there are many injuries at the same time.

Most commonly, seborrheic keratosis occurs in areas such as the head, neck, chest, or back. It most often affects people from middle age. It is estimated that 75% of those over 70 have this type of growth.

Seborrheic keratosis is also known as basal cell papilloma or seborrheic warts. These bumps are harmless, do not need treatment, and are not contagious.. Its appearance is similar to that of melanoma, so a biopsy is sometimes done before confirming the diagnosis.

What are the main causes?

Science has not established the exact cause of seborrheic keratosis. They are reported to have genetic mutations similar to those of multiple myeloma or ovarian cancer. Nevertheless, in this case there is no malignant potential.

The factors that could influence the formation of lesions are the following:

  • Sunlight: They usually appear in areas that are exposed to sunlight and that is why it is believed that ultraviolet (UV) light could influence.
  • Genetics: these skin growths are often hereditary.
  • Age: there is a relationship between the appearance of lesions and aging. Keratosis can appear at any age, but it is much more common after the age of 50.

Risk groups

People who are most at risk of developing this condition are, first of all, those who have a family history of seborrheic keratosis. As noted above, this problem is often hereditary.

On the other hand, the most common is that this type of injury appears in middle-aged and elderly people. Therefore, the risk increases as you get older.

Those who are frequently exposed to the sun are also at higher risk. People who work outdoors or do outdoor activities on a regular basis are more likely to develop these growths.

Solar radiation affects the skin in different ways, causing cellular changes that lead to specific injuries.

Read also: How to have healthier skin

What does seborrheic keratosis look like?

The appearance of seborrheic keratosis is that of a growth that begins small and rough. It then increases in size, thickens, and takes on a wart-like appearance. The most common is that they are brown, but they can also be in other colors.

The shape of the lesion is oval or round and almost always appears on the chest, scalp, back, abdomen, or face. There are several types of seborrheic keratosis lesions, each with distinctive characteristics:

  • Common: the lesions appear as if they have stuck to the skin and are very similar to a wart. They feel like wax or velvet to the touch.
  • Black papular dermatosis: they are black and raised grains. More common in women and dark-skinned people.
  • Stucco: lesions are gray and look like rough warts. They appear more in men and are usually located on the forearms and legs.
  • Flat: brown, oval patches that increase in number as you age.
  • Pedunculated: dark lesions that present a stem. They appear in the armpit or neck.

Discover: Actinic Keratosis: Causes, Symptoms and Treatment

When is medical help necessary?

At first, seborrheic keratosis is not dangerous and does not need treatment. However, a growth on the skin can never be overlooked. In this case, the lesion is very similar to a melanoma and that is why it is necessary for the doctor to make the diagnosis.

In the same way, it is advisable to go to the health professional in these cases:

  • Change in size or appearance of the injury.
  • Growth with a strange color, such as blue, purple, or reddish black.
  • Ragged edges.
  • Irritation or pain in growth.
  • Secretions
  • Development of many growths in a short time.
  • Bleeding in lesions.

Available treatments for seborrheic keratosis

Seborrheic keratosis as such does not require treatment from a dermatological point of view. Nevertheless, Injuries may cause discomfort from rubbing against clothing or with other surfaces. Or that they generate an aesthetic concern.

In those cases, the approach to follow is the elimination of growth. This can be done through one of the following procedures.


It consists of freezing the lesion with liquid nitrogen. It is applied with a cotton swab or spray gun. The lesion freezes and falls off on its own in a few days.

Sometimes a blister or scab forms, which also falls off later. It is not always effective with larger and thicker growths.


It is a scraping on the surface of the skin. The area is anesthetized first, and then the procedure is performed with a scalpel blade.

This sheet is called curette and is shaped like a shovel. In some cases, this method is combined with electrocautery, if necessary.


The removal is done with electrical current. The area is numbed with anesthesia, and then electricity is applied; this cauterizes the injury.

If not done properly, the procedure could leave scars. It is indicated for the thickest lesions.

The elimination of seborrheic keratosis with laser, photocoagulation or cryotherapy responds to aesthetic reasons.


It consists of vaporizing the lesion through the use of a laser. Low radiation flux is used. The surface of the skin becomes warm and eventually the growth evaporates.

It may or may not require anesthesia. It is a procedure in which great precision is achieved.

Hydrogen peroxide

It is a solution that is applied to the injury and that it is effective in eliminating seborrheic keratosis. However, it can also irritate the skin. The substance must be handled with care as it can damage the eyes.

Recovery and prognosis

It is common for the skin to appear slightly lighter in the area where the growth was removed, but this will normalize over time. Seborrheic keratosis will not return to that particular part of the skin, but it can recur in another region.

Treatments for these types of injuries are usually successful and do not leave scars. Changes in skin color after the procedure are usually more noticeable when they take place on the torso.

Seborrheic keratosis is not serious

Typically, the doctor diagnoses seborrheic keratosis with a routine physical exam. However, sometimes there may be doubts and a skin biopsy is needed to confirm the diagnosis.

When the seborrheic keratosis is very thin there is the possibility that it is a type of skin cancer known as malignant lentigo. If many lesions appear in a very short time, it is important to consult a doctor, as it can be a manifestation of cancer.