Actinic keratoses

Also known as solar keratoses

Actinic keratoses are rough scaly spots that develop due to sun and UV damage to the skin.

They tend to occur on areas such as the face, ears, scalp, forehead, hands and legs. Actinic keratoses represent abnormal skin cell development. They are pre-cancerous lesions and if left untreated, can sometimes progress to become squamous cell carcinoma. 

  • Actinic keratoses are most common in people with fair skin or those who have worked outdoors for long periods without skin protection.
  • The surrounding skin often shows other signs of sun damage with sun spots, dryness and wrinkles
  • On the lips they are often called actinic or solar cheilitis.

Causes

As the name suggests solar keratoses are due to sun damage from years in the sun or outdoors.

Treatment

The aim of treatment is to remove these abnormal skin cells to prevent them becoming skin cancers. New skin then forms from deeper cells that have escaped sun damage. If actinic keratoses are widespread, it may not be practical to treat all lesions and just focus on the most thickened, tender or annoying ones. The thicker and tender ones are also the ones at greatest risk of progressing to skin cancer.

Treatments may include:

  • Cryotherapy – freezing with liquid nitrogen. Very common treatment. Easy to do. May leave pale scar and often needs repeating. 
  • Curettage and cautery – may be preferred with thicker keratoses, and is a common method of removing early squamous cell cancers.
    • Curettage is the removal of a lesion by scraping it with a sharp instrument.
    • Cautery or diathermy is the use of heat to burn the keratosis and this approach prevents bleeding. A scab forms which heals over a few weeks, leaving a small scar.
  • Excision – this involves a small surgical procedure using local anaesthetic to cut the lesion out. This will often need a few sutures (stitches) which are removed 5 to 14 days later (depending on the location). 
  • Topical creams – a range of creams are now available and can be useful for treating areas that are not suitable for other treatments, or for large areas when multiple keratoses such as on the scalp, forehead or ears. Examples include: 5-Fluorouracil cream and Imiquimod. 
  • Photodynamic therapy – photodynamic therapy (PDT) involves applying a photosensitiser (a porphyrin chemical) to the affected area prior to exposing it to a strong source of visible light. The treated area develops a 'burn' and then heals over a couple of weeks or so. Metvix PDT is available in New Zealand.

Self care

The best option for preventing actinic or solar keratoses from developing or getting worse is to protect your skin from the sun and UV rays.

  • When outside between 10am and 4pm, keep covered with hat, sunglasses, long sleeves and pants.
  • Put 30+ or stronger broad spectrum sunscreen onto affected areas every day.
  • Protect your children from sun damage now. 
  • Watch out for high risk areas or activities – water sports, skiing, white concrete areas all reflect more sunlight.
  • Avoid sunbeds, UV tanning cabinets or artificial sunlamps.
  • Check your own skin every few months and see your doctor if any lesions start to itch, bleed, grow or change.

Learn more

Solar keratoses information sheet British Association of Dermatologists (UK),2013
Actinic keratoses NHS Choices (UK), 2014

Credits: New Zealand Dermatological Society Inc. (DermNet NZ). Updated by Health Navigator August 2014. Reviewed By: Editorial team Last reviewed: 16 Jan 2015