AK and actinic keratosis explained

These patches often develop on areas that have received repeated ultraviolet exposure, such as the face, scalp, ears, forearms and backs of the hands. They may feel rough before they look obvious and can vary in colour from skin-toned to pink, red or brown.

Actinic keratosis shows that ultraviolet exposure has altered cells in the outer skin layer. A patch may remain stable, settle, return or progress. Squamous cell carcinoma can arise in an actinic keratosis, but appearance alone cannot reliably show which individual patch will change.

A clinician usually examines the surface, thickness and surrounding skin. Dermoscopy may help with inspection. Biopsy can be considered when a lesion is unusually thick, tender, rapidly changing, ulcerated or uncertain, because a tissue sample can distinguish an AK from an invasive skin cancer or another condition.

Treatment depends on whether there is one defined patch or a broader field of sun-damaged skin. A clinician may freeze an individual lesion, remove or sample a thicker area, or prescribe a cream that treats visible and less obvious abnormal cells. Photodynamic therapy is another field-directed option in selected cases.

Use shade, protective clothing and broad-spectrum sunscreen on exposed skin, and avoid deliberate tanning. Check the treated site and the rest of your sun-exposed skin regularly. A lesion can recur, and new patches may appear elsewhere because treatment does not erase earlier ultraviolet damage.

Book a prompt skin assessment if a rough patch becomes thicker, grows quickly, bleeds without a clear injury, forms a persistent sore or becomes distinctly painful. Seek review as well when you are unsure whether a spot is new or when a treated area fails to heal as expected. These changes do not establish cancer, but they can justify closer examination or biopsy.

Ask whether the diagnosis is clear from examination or needs biopsy, whether treatment should target one lesion or a wider field, what skin reaction to expect, how to care for the area during healing, and when the site should be checked again.