What is seborrhoeic keratosis?
A seborrhoeic keratosis is a common benign (non-cancerous) skin growth. They tend to become more common with age and can occur on the face, chest, back, shoulders and other parts of the body.
They can look quite different from one person to another. Typical features include:
- A brown, tan, black or skin-coloured growth
- A rough, waxy or wart-like surface
- A lesion that appears to look as though it is “stuck onto” the skin
- They can be flat or raised
- Some are only a few millimetres across, while others become considerably larger
- A person may have one or many lesions
Are they dangerous?
Usually, no. Seborrhoeic keratoses are benign and do not themselves become skin cancer however, not every pigmented or raised lesion is a seborrhoeic keratosis. If you have experienced any of the following we recommend you speak to your GP.
- New or changing
- Rapidly growing
- Bleeding
- Persistently crusting
- Painful
- Very dark or unusually pigmented
- Different from any other lesions
Why do they develop?
The exact cause isn’t completely understood. Age is the strongest association, and genetics can play a role. They aren’t caused by poor hygiene and they aren’t contagious.
They can also appear in large numbers, sometimes quite suddenly, although a sudden eruption of numerous lesions warrants medical assessment rather than assuming they are all SKs.
Can seborrhoeic keratoses be removed?
Yes. If a seborrhoeic keratosis is bothersome, catches on clothing/jewellery, becomes irritated, or someone simply wants it removed for cosmetic reasons, there are several possible removal techniques.
Depending on the lesion and clinical assessment, these can include:
- Cryotherapy (freezing)
- Curettage (removing the lesion with a specialised instrument)
- Other clinician-selected techniques
The appropriate method depends on the size, thickness, location and appearance of the lesion.
