Seborrhoeic keratosis
Created: 09.01.2025
Updated 09.01.2025
Approved by: Consultant Dermatologist, Dr James Denny
What is a seborrhoeic keratosis?
A seborrhoeic keratosis, sometimes referred to as a seborrhoeic wart or basal cell papilloma, is a common benign (non-cancerous) skin growth. They are typically raised, with a waxy or scaly surface, and may vary in colour from light tan to dark brown or almost black. These growths can appear anywhere on the body but are most frequently seen on the trunk, back, scalp, face, or shoulders.
Because of their appearance, seborrhoeic keratoses can sometimes be mistaken for moles or other skin lesions, which can understandably cause concern. Importantly, they do not develop into skin cancer and are not considered a risk factor for melanoma or other malignancies.
Causes and risk factors
The exact cause of seborrhoeic keratoses is still not fully understood. Unlike viral warts, they are not caused by an infection and are not contagious. However, several factors are believed to play a role:
- Age – They are most common in adults over the age of 40 and become more frequent with advancing age.
- Genetics – Family history can play a part, and those with parents or siblings who have multiple seborrhoeic keratoses may be more likely to develop them.
- Skin type – People with lighter skin tones appear more likely to develop seborrhoeic keratoses, although they can affect all skin types.
- Sun exposure – While not a direct cause, chronic sun exposure may contribute to their development, particularly on sun-exposed areas such as the face and arms.
Understanding these risk factors can help individuals recognise when new lesions are likely benign, though any concerning change should still be assessed by a healthcare professional.
What are the treatments?
Seborrhoeic keratoses are usually diagnosed through a clinical skin examination by a dermatologist or GP, as their appearance is often very distinctive. In rare cases where the diagnosis is uncertain, a small sample (biopsy) may be taken to rule out other skin conditions, including melanoma.
Since seborrhoeic keratoses are harmless, treatment is not medically necessary. However, many people choose to have them removed for cosmetic reasons or because they become irritated by clothing or jewellery. Treatment options include:
- Cryotherapy – Freezing the growth with liquid nitrogen is a common, quick, and effective method.
- Curettage – Gently scraping the lesion away under local anaesthetic.
- Electrocautery – Using heat to remove the lesion.
- Surgical removal – Reserved for larger or recurring lesions.
Even after successful treatment, seborrhoeic keratoses can reappear over time, either in the same place or elsewhere on the body. Follow-up treatment is possible if needed.
Complications and prognosis
Seborrhoeic keratoses are benign and have an excellent prognosis. They do not turn into cancer and usually do not lead to medical complications. The main issues associated with them are:
- Irritation – Growths may become itchy, inflamed, or catch on clothing, causing discomfort.
- Cosmetic concerns – Some people seek removal because of the appearance or texture.
- Diagnostic confusion – In rare cases, a cancerous mole may resemble a seborrhoeic keratosis, which is why any rapidly changing, painful, or unusual lesion should be evaluated by a dermatologist.
Overall, the outlook is very good, and most people live with seborrhoeic keratoses without needing intervention.
When to seek medical advice
Although seborrhoeic keratoses are benign, it is important to have any new or changing skin lesions assessed by a healthcare professional. Seek medical advice if you notice:
- Rapid growth or change in colour or shape
- Bleeding, ulceration, or persistent pain
- New lesions appearing suddenly in large numbers
- Any doubt about whether a lesion is benign
Prompt evaluation helps rule out more serious skin conditions, including melanoma, and provides reassurance.
Frequently asked questions
Can seborrhoeic keratoses go away on their own?
No, seborrhoeic keratoses do not usually disappear without treatment. They may become flatter or less noticeable over time, but once formed, they generally remain unless removed.
Are seborrhoeic keratoses contagious?
No, they are not caused by a virus or infection and cannot be passed from one person to another.
Do I need to have them treated?
Treatment is not medically necessary unless the lesion becomes irritated, painful, or there is uncertainty about the diagnosis. Many people choose removal for cosmetic reasons.
Is there any way to prevent them?
Currently, there are no proven preventive measures. Protecting your skin from excessive sun exposure may help reduce the development of new growths on sun-exposed areas, but seborrhoeic keratoses can still occur.
Should I be worried if I develop several at once?
The sudden appearance of many seborrhoeic keratoses can occasionally be associated with underlying medical conditions, although this is rare. If this happens, it is advisable to consult a healthcare provider for further assessment.
