Seborrheic Keratoses

Seborrheic keratoses (SK) is a common skin growth that may look worrisome but is actually harmless. By understanding the causes, characteristics, and treatment options for seborrheic keratoses, individuals can make informed decisions about their skin health and take appropriate measures to address these benign growths if desired.

What Is Seborrheic Keratoses?

Seborrheic keratoses causes benign (non-cancerous) skin growths on the skin’s surface. Most begin as small, rough bumps on the skin, but can be smooth and flat. They tend to have a waxy, “stuck-on-the-skin” appearance. These lesions typically appear gradually as you age, most commonly on the body’s face, neck, chest, or back areas. It’s estimated 30% of individuals will have at least one growth by the age of 40, and a staggering 75% by the time they reach 70 years old.

Appearance and Characteristics

Seborrheic keratoses range in diameter from just a few millimeters to several centimeters across. Their color can range from skin-toned or yellow to shades of brown, black, or even a combination of hues. While seborrheic keratoses can occur singly, they often appear in groups or clusters, particularly in areas such as the scalp, under the breasts, along the spine, or in the groin region.

What Causes Seborrheic Keratoses?

The precise cause of seborrheic keratoses remains unclear, but researchers have identified several potential contributing factors:

• Age: The prevalence of seborrheic keratoses increases significantly with advancing age, suggesting a degenerative or age-related component.
• Genetics: The tendency to develop multiple seborrheic keratoses appears to run in families, indicating a genetic predisposition.
• Sun Exposure: Some studies suggest that prolonged exposure to ultraviolet (UV) radiation from the sun may increase the likelihood of developing seborrheic keratoses.
• Skin Friction: The appearance of seborrheic keratoses in areas prone to skin friction, such as body folds or areas where clothing rubs against the skin, suggests that friction may play a role in their development.
• Epidermal Growth Factor Receptor (EGFR) Inhibition: Certain medications used in cancer treatment, known as EGFR inhibitors, have been associated with an increased incidence of verrucal (warty) keratoses, including seborrheic keratoses.
• Genetic Mutations: Researchers have identified specific genetic mutations, such as those affecting the FGFR3, PIK3CA, RAS, AKT1, and EGFR genes, that may contribute to forming seborrheic keratoses.

It is important to note that viral or bacterial infections do not cause seborrheic keratoses and are not contagious.

Symptoms of Seborrheic Keratoses

In most cases, seborrheic keratoses are asymptomatic, meaning they do not cause physical discomfort or symptoms. However, some individuals may experience the following:

• Itching: Occasionally, seborrheic keratoses may cause itching or irritation, mainly if they are located in areas prone to friction or rubbing against clothing.
• Bleeding: The growths may bleed if irritated or caught on clothing, jewelry, or other objects.
• Self-conscious Feelings and Behaviors: While harmless, some individuals may find seborrheic keratoses unsightly or bothersome, especially if they are numerous or located in visible areas of the body.

In rare instances, the sudden appearance of multiple seborrheic keratoses in a short period, a condition known as “eruptive seborrheic keratoses,” may be associated with an underlying internal malignancy, such as gastric adenocarcinoma. This is called the “sign of Leser-Trélat,” although the correlation is not yet fully understood and may be coincidental.

Dermatologist Seborrheic Keratoses Evaluation

Experienced dermatologists can typically identify seborrheic keratoses through visual examination alone. However, further diagnostic measures may be necessary to distinguish these growths from other skin conditions or lesions in some cases.

Dermoscopy

If there is uncertainty regarding the diagnosis, a dermatologist may employ a dermoscope, a handheld lighted microscope, to examine the growth more closely. Dermoscopic features that may suggest a seborrheic keratosis include:

• Multiple orange or brown clods (due to keratin accumulation in surface crevices)
• White, milia-like clods
• Curved, thick ridges and furrows form a brain-like or cerebriform pattern

Biopsy

In cases where the growth resembles a potential skin cancer, such as basal cell carcinoma, squamous cell carcinoma, or melanoma, a biopsy may be recommended. This involves removing a sample of the growth or the entire lesion for microscopic examination by a pathologist.

Seborrheic Keratoses vs Actinic Keratosis

Unlike seborrheic keratoses, actinic keratoses are precancerous lesions caused by excessive sun exposure. While they may appear crusty and scaly like seborrheic keratoses, actinic keratoses tend to be less pigmented, flatter, and more likely to appear in clusters on frequently sun-exposed areas of the body. They also carry a small risk (5-10%) of progressing to squamous cell carcinoma if left untreated.

Seborrheic Keratoses vs Melanoma

While seborrheic keratoses do not turn into melanoma (a potentially deadly form of skin cancer), the two can sometimes be mistaken for each other due to their similar appearance. However, there are several key differences:

• Seborrheic keratoses often appear in multiple numbers, while melanomas are typically solitary growths.
• Seborrheic keratoses tend to have a distinct texture, while melanomas are generally smooth.
• Seborrheic keratoses have well-defined borders, whereas melanomas may have irregular or blurred edges.
• Seborrheic keratoses are usually uniform in color, while melanomas can exhibit multiple shades or asymmetrical color distribution.
• Seborrheic keratoses change slowly and gradually over time, while melanomas may grow and change rapidly.

Dermatologist Seborrheic Keratoses Treatment

Since seborrheic keratoses are benign and pose no health risks, they often do not require treatment unless they become irritated, catch on clothing or jewelry, or are considered cosmetically undesirable by the individual. When the dermatologist and individual determine the removal of seborrheic keratoses is the best option, the following techniques may be used:

• Cryotherapy: Cryotherapy involves applying liquid nitrogen, an icy substance, to the growth using a cotton swab or spray gun. The freezing process destroys the seborrheic keratosis, causing it to fall off within a few days or weeks. A blister may form beneath the growth and dry into a scab-like crust before falling off.
• Shave Biopsy or Excision: If a sample of the growth needs to be preserved for laboratory analysis, a shave biopsy or excision may be performed. The dermatologist carefully shaves off or surgically removes the growth, ensuring the tissue is sent to a laboratory for examination.
• Laser Therapy: Lasers offer an alternative to surgical removal by precisely burning and sterilizing the growth while sealing the surrounding tissue. Laser therapy is generally quick but may result in a sore wound during the healing process.
• Prescription Hydrogen Peroxide: The U.S. Food and Drug Administration (FDA) recently approved the use of a topical 40% hydrogen peroxide solution to treat seborrheic keratoses. The solution is applied to the growth using an applicator pen, and multiple applications may be required over multiple visits to achieve the desired results.

It is important to note that while these removal methods are generally safe and effective, they may result in temporary side effects such as scarring, changes in skin pigmentation, and wound care.

Seborrheic Keratoses Treatment by VitalSkin

Seborrheic keratoses are common, harmless skin growths that often develop as we age. While they may be a cosmetic concern or occasionally cause minor discomfort, they pose no significant health risks. However, it is essential to have any new or concerning skin growths evaluated by a dermatologist to ensure proper diagnosis and treatment, if necessary.

For those navigating the complexities of seborrheic keratoses, the path to clearer skin may require professional cosmetic intervention to achieve the best outcomes. Book an appointment with VitalSkinDermatology today to explore the most appropriate treatment options tailored to your needs.