Seborrheic keratoses (SK) are very common benign (non-cancerous) skin growths that often form with age. Their name reflects the appearance of these lesions, with seborrheic meaning greasy and keratosis meaning thickening of the skin.

Although they are not precancerous, these brown barnacle-like lesions may look similar to actinic keratosis that can sometimes turn into squamous cell carcinoma skin cancer or mimic cancerous skin growths like melanoma and pigmented basal cell carcinoma.

These skin growths are very common with advancing age, most frequently appearing on areas like the forehead, neck, and trunk and in skin creases. A US-based study found that at least 88% of the people older than 64 years of age had at least one SK.

Functional medicine takes a holistic approach to skin conditions such as SK taking into account personal and family history, lifestyle, diet, social factors, and even emotional health. This use of functional medicine for seborrheic keratosis allows for a personalized approach that benefits the skin and overall health. 

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What is Seborrheic Keratosis?

Seborrheic keratoses are non-cancerous (benign) tumors that form in the outer layer or epidermis of the skin. They form due to the proliferation of clusters of extra cells called epidermal keratinocytes and grow slowly over time. They are most commonly found on the face, especially the forehead, neck, and trunk. 

These skin lesions look similar to moles, forming roundish or oval-shaped patches on the skin that appear to be “stuck on.” SKs are most commonly brown but can also be black or tan, and less frequently, pink, yellow, or white. 

They are usually raised above the surrounding skin and may appear scaly or waxy due to the keratin that deposits on their surface. This fibrous protein also makes up fingernails, hooves, and horns, so seborrheic keratoses can often be palpated with a rough or wart-like texture.

These growths are sometimes known as senile warts since they are very common with advancing age. Around 83 million Americans experience seborrheic keratosis. The majority of people will develop at least one SK as they age and often many will form. Overall, at least 30% of people have one or more SKs by the age of 40 with about 75% of people over age 70 experiencing these growths.

Seborrheic keratosis is conventionally diagnosed with a skin exam from a dermatologist. They may examine the skin using dermoscopy with a small, handheld lighted microscope to differentiate SKs from other similar-appearing lesions. If there is doubt in the diagnosis of SK and cancer or pre-cancer is suspected at all, a skin biopsy can be taken to examine the tissue under a microscope in the laboratory to give a definitive diagnosis.

While SKs are not harmful, they can be removed with minor surgery, including cryosurgery (freezing with liquid nitrogen), shave excisions, and laser-assisted removal if they are causing irritation or distress. Topical therapies are also sometimes used as discussed below.

The Functional Medicine Perspective on Skin Health

A holistic approach to seborrheic keratosis can support improvements in skin health and restore greater balance to the body as a whole. Most skin conditions, including seborrheic keratosis, involve several interacting factors that contribute to their development. 

Your skin provides a barrier between you and the outside world, helps to regulate temperature, and regulates moisture levels in your body. As the largest organ in your body, your skin is influenced by many factors and the state of other body systems. Imbalances caused by systemic inflammation, nutritional deficiencies, microbiome dysregulation, food sensitivities, hormone levels, and stress can significantly impact the state of your skin.

A functional medicine approach seeks to identify lifestyle, environmental, and genetic factors that contribute to skin conditions like SK. Looking at the range of contributing underlying factors and assessing the body's systems holistically can help bring the skin and body back into balance. 

Identifying Underlying Causes of SK

While the exact etiopathology of SK is still under investigation, seborrheic keratosis is thought to develop due to an interaction between genetic predispositions, hormonal factors, and sometimes chronic UV-radiation exposure. Various causes of seborrheic keratosis can be investigated by taking a thorough personal and family history and using functional testing for skin conditions and related health issues.

There is a tendency for people with a family history of SKs to develop many of them, suggesting that a predisposition may be inherited. In addition, SK lesions often show non-malignant mutations of fibroblast growth factor receptor 3 and other signaling molecules.

Hormonal factors also play a role in the development of these lesions. Seborrheic keratosis is more likely to develop during pregnancy and with estrogen replacement therapy. The DUTCH test can be used to look at hormonal balance and measure various estrogen metabolites.

With age, changes occur in your skin and most people are cumulatively exposed to increasing amounts of UV damage from sun exposure and other changes in the skin’s surface. Studies suggest that UV-exposed skin can develop an overexpression of amyloid precursor protein that is associated with skin again and can promote the formation of the adenoid subtype of SK, although SKs can also develop on skin protected from the sun.

While SKs can appear wart-like, they are not usually due to a viral or bacterial infection and are not contagious. Sometimes, SK lesions on the genitals may be associated with HPV infection and reduced local zinc concentration. Zinc levels can be measured in the blood with Access Medical Laboratory’s zinc red blood cell (RBC) test. 

Another nutrient that is important for skin health is vitamin D. This vitamin is important for proper immune function and preventing skin damage and cancer. Vitamin D can be measured in the blood to identify when repletion of low levels is needed.

Dietary and Nutritional Interventions

Nutrition significantly impacts the health of your skin and how skin ages. Dietary strategies can impact skin health and potentially reduce the risk or severity of SK. A balanced diet focused on anti-inflammatory foods, antioxidants, and specific nutrients helps to support skin integrity and reduce inflammation throughout the body.

A nutrient-rich anti-inflammatory diet helps to keep skin healthy in many ways. Fruits and vegetables containing antioxidants like polyphenols and vitamins C, E, and A, as well as omega-3 fatty acids, can help to reduce inflammation, mitigate damage caused by UV exposure from the sun, and help skin age well. You can consume foods like cold-water fatty fish, walnuts, chia seeds, and flaxseeds to add omega-3 fatty acids to your diet.  

Additionally, nutrients like zinc and vitamin D are important for skin health. Oysters and other seafood, eggs, dairy products, beans, nuts, and whole grains are natural sources of zinc. Good food sources of vitamin D include grass-fed beef liver, fatty fish like salmon, and mushrooms.

Avoiding inflammation-promoting foods like conventionally-raised meats and dairy products, trans fats, ultra-processed foods, simple sugars, and chemical additives and preservatives helps to reduce overall inflammation in the body including in the skin. It is also helpful to avoid foods to which you are sensitive or allergic. Food sensitivities can disrupt the intestinal barrier and contribute to dysregulation of immune and inflammatory responses, impacting skin health.

Lifestyle Modifications to Support Skin Health

Improving skin health naturally involves integrating lifestyle practices that support skin health on many levels. Practicing meaningful stress management strategies, ensuring plenty of high-quality restorative sleep, being mindful about sun exposure, and integrating regular physical activity supports skin health and overall wellness.

‍Stress significantly impacts your skin. It can do so by disrupting the microbiome and contributing to a leaky gut, which creates increased inflammation throughout the body including in the skin via the gut-skin axis. In addition, stress involves many hormonal and chemical mediators like cortisol that can contribute to hormonal imbalances and inflammation. Chronic stress can lead to premature skin aging and associated conditions like seborrheic keratosis. 

Regularly practicing meaningful stress management can help to reduce the negative impacts that stress can have on your skin. Mind-body practices like meditation, yoga, and breathwork offer strategies that reduce stress and inflammation, promote relaxation, enhance coping mechanisms, and improve skin health. 

Ensuring that you get enough regular restorative sleep is also crucial for managing stress, keeping your gut healthy, and maintaining skin health. Aim for at least 7-9 hours of sleep each night on a regular schedule. 

In addition to mind-body practices and regular adequate sleep, physical activity helps to keep your skin healthy. Exercise has many benefits for the skin and overall health, regulating inflammation and helping you reduce chronic stress. Exercise is also important for balancing hormones like estrogen. Moving regularly also helps promote gut health and benefits the microbiome, an impact that has wide-ranging impacts on skin health as well. 

Reducing the time you spend in the sun’s strongest rays between 10 am and 4 pm reduces your exposure to the most harmful UVB radiation to help minimize damage and aging of your skin. You can also utilize sun-protective clothing and wear a wide-brimmed hat to protect the delicate skin of the face.

Topical and Natural Remedies

Topical treatments and natural remedies have been used to help reduce SK and promote skin health. Topical treatments for seborrheic keratosis include conventional prescriptions and more natural remedies which are less invasive alternatives to surgical removal. It is important to work with a knowledgeable practitioner to discuss the most appropriate remedies for your needs.

Topical remedies such as 40% hydrogen peroxide (HP40) and an aqueous nitric–zinc complex have been shown to effectively help resolve SK lesions. Hydrogen peroxide is believed to work on SK lesions by generating reactive oxygen species that cause the death of the proliferating cells. Nitric-zinc complex (Nitrizinc Complex) contains nitric acids, zinc, copper salts, and organic acids which are topically applied to reduce SK growths. After eight weeks of treatment with Nitric-zinc complex, 74% of SK lesions achieved complete clinical and dermoscopic clearance and did not recur.

Vitamin D-based topical treatments have also shown promise for reducing SKIN lesions. Vitamin D creams like Calcipotriol (Calcipotriene) applied topically for 3-12 months have been shown to reduce the size of SK growths by over 80% with no redness, swelling, or scarring.

Vitamin A-based topical treatments like Tazarotene 0.1% cream, a retinoid derived from vitamin A, have also shown efficacy in reducing SK lesions. Applying this cream topically to SK lesions twice a day for four months resulted in significant improvement, although it did cause some irritation. 

Zinc is an important nutrient for normal cell function and eliminating virus-infected cells and tumor cells. In some cases of SK, especially those associated with HPV virus, topical application of zinc oxide ointment for four months has been shown to reduce skin lesions by 90%.

Integrative and Complementary Therapies

Integrative and complementary therapies for SK can help manage overall skin health and support well-being. Integrative treatment for skin health such as acupuncture and phototherapy may be part of a holistic treatment plan. Studies suggest that integrative therapies such as ultrasound, laser, photodynamic therapy (PDT), and acupuncture are effective treatment options for SK.

High-intensity focused ultrasound at 20 MHz has been used as a safe and efficient treatment for a range of skin conditions including SK. This non-invasive method is safe and effective for the removal of seborrheic keratosis. Similarly, laser treatments and photodynamic therapy (PDT) use focused light energy to successfully remove SK lesions.

Acupuncture is a practice in Traditional Chinese Medicine that has been used for centuries to improve skin health and reduce aging of the skin. Acupuncture can reduce wrinkles and edema, improve facial muscle tone, and smooth out skin texture to improve the appearance and health of the skin.

Empowering Patients in Their Care

Since seborrheic keratosis can mimic other more dangerous conditions, educating and empowering patients to know their bodies and pay attention to their skin health is important. This gives patients agency as partners in their care and helps them get to know and feel comfortable with paying attention to their skin and bodies.

Education on seborrheic keratosis can help people monitor their skin for any changes that may indicate the need for evaluation. SKs can resemble other skin conditions including skin cancers like melanoma and pigmented basal cell carcinoma and are often very similar in appearance to actinic keratosis that can sometimes turn into squamous cell carcinoma skin cancer.

People must be educated about the appearance of skin changes and seek care if they notice a new, unidentified growth or if an existing seborrheic keratosis changes its appearance or starts itching or bleeding. 

An evaluation by a health professional is also important if many SK-appearing growths develop suddenly in a short period. Normally SKs develop and grow slowly over time, but when many seborrheic keratoses erupt suddenly together it is known as “the sign of Leser Trélat” and has sometimes been associated with internal cancers. 

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A Functional Medicine Approach to Seborrheic Keratosis: Key Takeaways

Seborrheic keratoses are the most common benign skin tumors and are increasingly common with age. These brown, rough, raised lesions are not cancerous but should always be differentiated from skin cancers like melanoma and pre-cancerous lesions like actinic keratosis.

A comprehensive approach to seborrheic keratosis utilizes holistic consideration of dietary, lifestyle, and integrative therapies alongside conventional treatments. This includes functional medicine testing that looks for root causes and identifies underlying factors that may contribute to the development of these common skin lesions. This allows for a more targeted approach to treating SK and preventing future lesions.