What is solar keratosis?

Solar keratoses (SKs) (sometimes referred to as actinic keratoses or sun spots) are rough skin patches that develop where the skin has been exposed to the sun over time. Some SKs you can see, some you can only feel and some are invisible. Your skin never forgets – it can take years or even decades for sun damage to appear in the form of visible SK lesions.

It is rare to find just one SK – SK may appear as a discrete patch; however, multiple patches over large areas of skin are also common.


Solar keratosis may get better on its own but, in a small number of cases, it can lead to non-melanoma skin cancer (NMSC) including:


  • Basal cell carcinoma (BCC) is the most common type of skin cancer. It often appears as a small, red or pearly lump that may grow slowly and rarely spreads
  • Squamous cell carcinoma (SCC) is less common than BCC but generally faster growing. This form of skin cancer may occur on all areas of the body, but generally appears on those that have been most exposed to the sun. There is a risk of SCC spreading to deeper layers of the skin

It is impossible to tell which SK patches have the potential to become cancerous, which is why it is so important to check your skin regularly and discuss any signs of change with your doctor.

How well do you know your skin?

Visible signs of SK can vary and for some people you may only be able to feel the patch. The colour may also vary, from a barely noticeable darkening in skin colour to a more obvious red.

SKs vary in size and can be scaly or plaque like, or feel like sandpaper. For some people, SKs may be itchy and tender.

Look for patches of skin that:

  • Change in size
  • Change in shape
  • Change in colour
  • Feel like sandpaper
  • Are red/inflamed
  • Feel painful
  • Itch
  • Bleed

These images show examples of SK patches. Don’t forget to regularly look at and feel your skin for changes. 

Images are published with the permission of the New Zealand Dermatological Society Incorporated.