What Is a Seborrhoeic Keratosis?
Seborrhoeic keratoses (also called seborrhoeic warts, senile warts, or verruca senilis) are benign skin growths that become increasingly common from middle age onwards. Despite the name "wart," they are not caused by a virus and are not contagious. They arise from the keratinocytes (skin cells) in the outer layer of the skin and have no link to skin cancer.
They tend to appear on the trunk, shoulders, face, and scalp — areas of the skin that receive the most sun exposure over a lifetime, though sun exposure is not the primary cause. Most people develop at least a few during their lifetime; some develop hundreds.
What Do They Look Like?
Seborrhoeic keratoses are characteristically described as looking "stuck on" — as if someone has stuck a piece of brown, waxy material to the skin. Key features include:
- Colour ranging from pale tan to dark brown or almost black
- A warty, rough, or velvety surface texture
- Well-defined, often rounded or oval borders
- Size from a few millimetres to several centimetres
- Often slightly raised above the surrounding skin
- May have a greasy or waxy appearance
- Tiny white cyst-like structures visible on the surface (milia-like cysts) under close examination
They can be itchy, particularly when they rub against clothing, and occasionally bleed if traumatised. They do not become skin cancer.
Can They Be Confused With Melanoma?
Yes — and this is the most important clinical point. Seborrhoeic keratoses are one of the most common lesions to be referred to dermatology because they can look alarming, particularly when they are dark, pigmented irregularly, or in a location that makes them easy to notice.
When to seek assessment rather than wait: If you have noticed a pigmented lesion that is new, changing, or simply unfamiliar — even if you suspect it is benign — a GP assessment with dermoscopy provides certainty. Dermoscopy reveals characteristic seborrhoeic keratosis features (milia-like cysts, comedo-like openings, sharp borders) that distinguish them from melanoma with a high degree of accuracy.
If there is any clinical uncertainty after dermoscopic assessment, your GP will refer rather than remove — this is the safest approach. The reassurance that comes from a confirmed diagnosis has genuine value.
Why the NHS Rarely Removes Them
Seborrhoeic keratoses are classified as cosmetic skin conditions by the NHS, meaning they do not meet the criteria for routine removal on clinical grounds (because they are benign and pose no health risk). NHS dermatology services prioritise conditions with cancer risk or significant functional impairment.
Private treatment allows removal for cosmetic reasons — to eliminate a lesion that catches on clothing, attracts unwanted attention, or simply causes the patient distress.
Treatment Options
All seborrhoeic keratosis removal is performed after confirmed clinical assessment. Your GP will first confirm the diagnosis with dermoscopy before any removal is planned.
Cryotherapy
Liquid nitrogen is applied to freeze the lesion. It blisters and falls off within 2–4 weeks. Best for thinner, flatter lesions. May require a repeat session for thick lesions.
Curettage
The lesion is scraped away under local anaesthetic using a curette. Effective for thicker, raised lesions. Quick procedure, minimal healing time.
Shave Excision
The lesion is shaved off at skin level under local anaesthetic. Provides a tissue sample for histology. Leaves a flat, usually barely visible scar.
Book an Assessment
If you have a skin growth that looks like a seborrhoeic keratosis and would like confirmation or removal, Lambert Medical Practice offers a prompt dermatology assessment with dermoscopy. No GP referral needed.