Seborrheic keratosis is one of the most common benign skin growths, particularly among older adults. It usually presents as wart-like lesions, and there are often a lot of them which keep increasing over time. Seborrheic keratosis tends to cause concern mostly for cosmetic reasons, or because of worries about whether it could be something more sinister. In this article we explore exactly what seborrheic keratosis is, along with its causes, prevention and the best treatments for removal. We will also look at how to tell seborrheic keratosis apart from actinic keratosis and other precancerous or malignant conditions.
What is Seborrheic Keratosis?
Seborrheic keratosis is a non-cancerous (benign) skin growth that typically appears as a brown, black or pale raised area. These growths can vary in size from tiny spots to large patches and often resemble warts. They usually have a waxy, scaly, slightly elevated surface that may look stuck onto the skin. People often describe it as looking almost as if someone dabbed a blob of wax onto their skin. The most common features are:
- Appearance: The colour ranges from light tan to black and the texture can be rough or smooth. The growths often, but not always, have a wart-like appearance.
- Location: Seborrheic keratoses most commonly occur on the face, chest, shoulders and back. However, they can develop anywhere on the body except the palms and soles.
- Growth patterns: These growths often appear in multiples and can increase in number and size over time.
- Safety: Although they may look unsightly, these lesions are entirely benign and not associated with skin cancer.
What’s the Difference Between Seborrheic Keratosis and Actinic Keratosis?
Seborrheic keratosis is very often confused with actinic keratosis, which is a more serious condition. Although seborrheic keratosis is benign, actinic keratosis is a precancerous condition that has the potential to progress to skin cancer. It is vital to understand the difference, and you should always see a doctor if you find any new skin lesions. In general, the key differences are:
- Causes: Seborrheic keratosis is primarily a result of genetic factors and age. The cause of actinic keratosis, by contrast, is usually different. It often comes from ultraviolet (UV) radiation, whether from the sun or from tanning beds.
- Appearance: Seborrheic keratosis is usually brown or black with a stuck-on look. Actinic keratosis tends to present as rough, scaly patches that can be red, pink or brown. Actinic keratosis is also flatter and less well-defined than the often elevated seborrheic keratosis.
- Health risks: Seborrheic keratosis is benign and does not pose a risk of cancer. Actinic keratosis, on the other hand, can develop into squamous cell carcinoma, which is a type of skin cancer.
Beyond actinic keratosis, there are other potentially cancerous skin lesions that can look similar to seborrheic keratosis. Skin cancers such as melanoma often present differently. They tend to be rapidly growing, irregularly shaped lesions that may change in colour, size or texture over time. These lesions may also bleed or ulcerate. Either way, it is always best to see an experienced doctor to help make the correct diagnosis.
What’s the Difference Between Seborrheic Keratosis and Warts?
It is also easy to mistake seborrheic keratosis for warts. The rough, raised and waxy appearance looks similar, and the lesions can be just as numerous. However, there are distinct differences between the two:
- Origin: The human papillomavirus (HPV) causes warts and makes them contagious. They can spread to other areas of skin, and even between people through contact. Seborrheic keratosis, on the other hand, is not caused by a virus and is not contagious.
- Appearance: Both can appear as rough, elevated lesions. However, warts tend to have a more cauliflower-like surface, whilst seborrheic keratosis has a waxy, stuck-on look.
As with any new skin growth, it is always wise to consult a doctor first to ensure a proper diagnosis. This matters because the treatment can differ between seborrheic keratosis and warts.
What Causes Seborrheic Keratosis?
It is largely influenced by genetics and age. It is more common in people over the age of 50, though it can appear earlier. In general, the main contributing factors are:
- Genetic predisposition: This condition tends to run in families, which suggests a genetic component. If your parents or siblings have the growths, you are more likely to develop them too.
- Ageing: The likelihood of developing seborrheic keratosis increases with age. This is why it is often nicknamed the barnacle of ageing.
- Sun exposure: UV radiation is not a direct cause. However, some studies suggest it may play a role in triggering these growths, particularly in areas frequently exposed to the sun. That said, the relationship between sun exposure and seborrheic keratosis is not as clear-cut as it is with actinic keratosis.
Can You Prevent Seborrheic Keratosis?
There are no surefire ways to prevent seborrheic keratosis, because of its strong genetic component and natural link with ageing. Whilst you cannot reliably stop these benign growths from forming, you can still support your overall skin health. This may reduce the likelihood of developing multiple lesions. Firstly, protect your skin from excessive sun exposure through regular use of sunscreen, wearing protective clothing and avoiding peak sun hours. This matters because UV radiation can sometimes play a role in the appearance and worsening of skin lesions. Secondly, try to maintain a consistent skincare routine that includes gentle cleansing, exfoliating and moisturising. This can keep your skin in good condition and improve its overall appearance. It may also reduce the visibility of and discomfort from existing lesions.
How Do You Get Rid of Seborrheic Keratosis?
These growths are generally harmless and do not require treatment unless one becomes irritated, itchy or bothers you cosmetically. A doctor may also recommend removal for biopsy if there is any concern about the diagnosis. This is to rule out conditions like melanoma or actinic keratosis. The main treatment options for reducing or removing these lesions are:
- Cryotherapy: This is one of the most common treatments for seborrheic keratosis. It involves freezing the growth with liquid nitrogen, which causes it to fall off over time. It is quick and relatively painless. However, it may leave a lighter or darker spot on the skin, which should return to normal with time. Larger lesions may also need follow-up treatments.
- Laser therapy: This method uses laser light to remove the growth. It is precise and effective, especially for larger or more stubborn lesions, and it minimises damage to surrounding tissue. However, it may require a few sessions for complete removal.
- Curettage: This is a minor surgical option that involves scraping off the growth with a special instrument called a curette. It is often combined with electrosurgery to burn off any remaining tissue, which ensures the lesion is fully removed.
- Electrosurgery: This method uses electrical currents to burn off the lesions. It is particularly effective for larger growths, or those that are difficult to remove with other methods.
- Topical treatments: Although less commonly used, certain topical solutions like tretinoin and hydrogen peroxide can help remove or shrink seborrheic keratoses. These options are less studied. They often need a long period of treatment and some trial and error to find the right one for you.
The choice of removal method depends on the size, location and number of growths, as well as personal preference. Where a diagnosis is needed, biopsy, curettage or excision let a doctor send an undamaged sample for study in the laboratory. Curettage and electrosurgery usually need a little aftercare for the treated area to prevent infection and promote healing. This includes keeping the area clean, applying any prescribed ointments and avoiding sun exposure until it is fully healed.
Despite its sometimes alarming appearance, seborrheic keratosis is a common and benign skin condition that poses no serious health risks. That said, it is important to tell it apart from conditions like actinic keratosis, melanoma and warts. These have very different implications for treatment. Whilst you cannot really prevent it, there are many removal options if the lesions bother you. Either way, always get any new skin growth checked by your medical provider first. This makes sure there is nothing more sinister going on.
City Skin Clinic is an online clinic. This means we do not offer in-clinic procedures like cryotherapy, curettage, laser or electrosurgery to remove these growths. If a growth bothers you, or you are not sure what it is, the safest first step is to see your GP or a dermatologist. They can confirm the diagnosis and remove it if needed. What our doctors do offer is personalised topical prescription skincare for concerns like acne, hyperpigmentation, melasma and skin ageing. If one of those is on your mind, you can use our online skin consultation form or book a video consultation. The journey towards great skin starts here.
This article is intended for general informational purposes only and is not a substitute for medical advice, diagnosis or treatment. Always consult a qualified medical professional with any concerns about your skin or treatment options.
