Seborrheic Keratosis

Seborrheic keratoses, also known in medical terms as singular seborrheic keratosis, are skin lesions than can look very bad but are not actually dangerous and never turn into cancer. They are more of an annoyance than a threat and can be found in many variants, they are sometimes barely visible but can also look like very large black areas. A popular name of these benign lesions is skin barnacles.

These skin lesions are easily confused with other conditions but they have a few typical symptoms. Even in medical books, their appearance is described in rather popular terms. They look like a piece of clay or dirt that was applied on the skin surface. Their edges are not actually connected to the skin, which gives the misleading impression that you can simply remove them with your nails. Unlike warts, which are rooted deep inside the skin, seborrheic keratoses only grow from the topmost skin layer, the epidermis.

While the skin lesions might look similar to warts, they are not caused by the papilomavirus that is the real trigger for them. They can have a very irregular surface, covered with deep cracks. Sometimes, the appearance is similar to a cauliflower. However, not all of them are rough and some can have a smooth surface. Smooth ones have distinctive small bumps with a different color than the surrounding skin. These look similar to tiny seeds are are known under the popular name of horn pearls. These small bumps are actually made up of keratin, the main building block of skin and nails, growing in circular patterns. Using a magnifying glass, the keratin bits can be seen very clearly.

Seborrheic keratoses are usually itchy and this problem intensifies with age. This makes some people scratch or try to remove the lesions, which only causes more irritation and increases the sensation of itching.

Severe irritation can eventually cause the seborrheic keratoses to become red and inflamed, eventually bleeding. This is a very worrying sign, since any skin bleeding is potentially dangerous and must be reported to a doctor.

Seborrheic keratoses vary in size from very small to over an inch in diameter. They are easily confused with other skin problems such as moles, warts or even cancer. While the lesions don't hurt, they can become inflamed and are usually itchy.

Even though their characteristics are variable, the lesions caused by seborrheic keratosis have some common features. They can range in size from tiny to over 1 inch across. They can be located anywhere on the skin, with the exception of palms of the hands and feet soles. The usual areas affected are the chest, back, abdomen, scalp or shoulders. Initially, the growths are very small and have a rough appearance. Their size increases in time and they begin to look similar to warts. Typically, they look like foreign objects glued on the skin, sometimes with a waxy look. Their color is usually brown but lesions can also be white, yellow or black. The shape is usually regular, either oval or round.

Seborrheic keratosis is usually not painful. However, the location of the lesions can make them very uncomfortable. You should not scratch them, even if they are itchy, to prevent bleeding and infections.

Causes of seborrheic keratosis

The causes of this condition are not very clear but some factors that include the risks and are potential root causes have been identified.

Since the skin lesions affect mostly those parts of skin that are exposed to sunlight, this appears to be one of the main risk factors. Dermatologists have also noticed that areas that are rarely or never exposed to the sun are not immune, so sunlight is not the only cause.

The condition also affects people from the same families, so there is possibly a genetic cause. The faulty gene or mutation that causes it has not been identified yet. Finally, age is a proven risk factor, since people aged over 50 are a lot more likely to develop seborrheic keratoses.

Scientists have also noticed that some gene mutations are shared by this condition with skin cancer and ovarian cancer. However, most of them agree that these mutations have a very low malignant threat. So far, no virus that could cause this disease has been detected. Since lesions are sometimes located in skin folds, friction appears to increase the risk.

Treatment options

Since seborrheic keratosis is normally harmless, no treatment is needed in most situations. Doctors decide to remove them in some cases, usually because the patients want to get rid of them. Sometimes, it is very hard to distinguish one of these harmless lesions from skin cancer, so they are eliminated just in case. They might also become irritated and itchy, especially when found in sensitive locations or when they are rubbed by clothes or accessories. Seborrheic keratosis is also removed when a biopsy is performed, since it solves two issues at the same time.

Doctors can choose between several modern and effective methods to eliminate seborrheic keratosis. Cryosurgery is performed by placing liquid nitrogen on the lesion using a spray gun or other methods. This kills the cells and freezes the growth, causing it to fall off after several days. If a blister develops on the spot, it is also harmless and will also dry and fall off soon.

Electrocautery or electro surgery implies the cauterization of the lesion using high voltage electric power. This can be very painful, so a local anesthesia is needed. The burnt lesion is then removed with a curette, which is a specific surgical tool. Sometimes, curettage is enough to remove seborrheic keratosis, while in other cases only electrocautery is required. However, in most cases both techniques are used. Another possibility is the use of a powerful laser to completely destroy the growth, a procedure named ablation.

None of these methods is perfect. The skin in the former location of the seborrheic keratosis can be lighter than the rest, which leads to a permanent discoloration scar. None of these techniques is able to remove more than one lesion, so multiple interventions might be required. Once a lesion is eliminated it rarely grows back. However, the condition might persist and new growths can emerge on other parts of the skin.