They can vary quite a bit in appearance but typically:

• Look stuck on the skin, like a piece of brown, tan, or black wax or barnacle

• Range from a few millimetres to several centimetres in size

• Have a rough, warty, or velvety texture

• May appear flat at first, then become raised and thickened over time

• Can occur anywhere on the body except the palms and soles. Most commonly on the face, chest, back, and shoulders

No. Seborrhoeic keratoses are completely benign and do not turn into skin cancer. However, it is important that any new or changing spot be checked by a doctor, as they can sometimes resemble more serious conditions like melanoma.

The exact cause isn't fully understood, but they tend to run in families and become more common and numerous with age. Sun exposure may play a role, though they can appear in sun-protected areas too.

No treatment is necessary unless they are causing problems such as:

• Irritation or itching from clothing rubbing against them

• Bleeding from scratching

• Cosmetic concern

If removal is desired, your doctor may recommend one of the following options:

• Cryotherapy (freezing): liquid nitrogen is applied to freeze and destroy the growth

• Electrotherapy (diathermy): a small electric current is used to burn off the lesion

• Shave biopsy: the lesion is numbed and shaved off at skin level with a blade, which also allows the tissue to be examined under a microscope

See your GP or dermatologist if a lesion:

• Changes rapidly in size, shape, or colour

• Bleeds without obvious cause

• Looks very different from your other keratoses

• You are simply unsure about

YourSkin Clinic offers bulk billed skin checks for pension card holders (as of may 2026).