What should you know about actinic keratosis and skin cancer?

A dermatologist cannot reliably predict which individual patch will progress by appearance alone. Assessment matters because early skin cancer may resemble a thick, inflamed, or persistent actinic keratosis, and a person can have both types of lesion in the same sun-damaged area.

Actinic keratosis develops after cumulative ultraviolet injury changes keratinocytes, the main cells in the outer skin layer. It can present as a rough, scaly, crusted, pink, red, brown, or skin-coloured patch on frequently exposed areas such as the face, scalp, ears, forearms, and backs of the hands. Some patches are easier to feel than see.

Squamous cell carcinoma occurs when abnormal keratinocytes become invasive. Features that raise concern include increasing thickness, a firm or rapidly growing bump, persistent soreness, bleeding, or ulceration. Those features do not establish cancer on their own; examination and, when indicated, a biopsy clarify the diagnosis.

Book a skin examination rather than peeling or picking the lesion. A dermatologist will assess the spot and nearby sun-damaged skin, then decide whether it can be treated clinically or needs a sample. Photographing the area and recording changes can make the history clearer.

Treatment may target one lesion or a wider field containing visible and early changes. Options can include cryotherapy for a discrete patch, topical fluorouracil or imiquimod for a broader area, and photodynamic therapy in suitable patients. The expected inflammation, aftercare, healing pattern, and cosmetic outcome differ, so the choice should reflect lesion location, extent, skin health, and personal circumstances. Ongoing sun protection helps limit further ultraviolet injury but does not remove an existing lesion.

Request prompt assessment if a patch grows quickly, becomes firm or markedly thick, bleeds without an obvious injury, forms a persistent sore, or becomes newly painful. A lesion that returns after treatment or behaves differently from nearby spots also deserves review. Seek urgent care for uncontrolled bleeding or signs of significant infection, including spreading redness with fever or worsening swelling.

Ask whether the patch is clinically typical of actinic keratosis, whether any feature warrants biopsy, and whether treatment should focus on the single spot or the surrounding field. Other useful questions cover likely skin reactions, wound care, reasons to return earlier than planned, and how often your skin should be checked based on your findings and history.