Topical Treatments for Actinic Keratoses: What to Expect

Actinic keratoses (AKs) are precancerous lesions caused by long-term sun exposure. If left untreated, some may progress to skin cancer, mainly squamous cell carcinoma. While some AKs are treated individually with cryotherapy (“freezing”), topical medications are often used when there are multiple lesions or widespread sun damage.

These treatments help address not only visible lesions, but also early microscopic precancerous changes that may not yet be obvious on the skin.

Why Are Topical Treatments Used?

Topical medications are sometimes recommended when patients have larger areas of sun damage, often called “field damage.”

Commonly treated areas include:

• face
• scalp
• forehead
• nose
• cheeks
• ears
• forearms

Treating the entire affected area may help reduce the number of visible and subclinical actinic keratoses.

What Medications Are Commonly Used?

Several topical medications may be used depending on the clinical situation.

5-Fluorouracil (5-FU)

5-FU is one of the most commonly used and effective treatments for actinic keratoses. It works by targeting abnormal sun-damaged cells.

During treatment, the skin often becomes:

• red
• inflamed
• crusted
• irritated

Although the reaction may look dramatic, this is often an expected part of treatment.

Imiquimod

Imiquimod works differently from 5-fluorouracil by stimulating the immune system to recognize and target abnormal sun-damaged cells.

Treatment schedules vary depending on the formulation and the area being treated. Some patients develop redness, crusting, irritation, itching, or tenderness during therapy, although reactions are often somewhat less intense than with 5-FU.

Imiquimod may be particularly useful in selected patients with multiple actinic keratoses or certain superficial skin cancers.

Other Topical Options

Additional topical treatments, including combination therapies, may be used depending on the extent of sun damage, prior treatment history, and patient preference.

Tirbanibulin

Tirbanibulin is a newer topical medication used for selected actinic keratoses. Treatment courses are generally shorter than with some older therapies, although individual responses may vary.

Diclofenac

Diclofenac gel is sometimes used for thinner or less extensive actinic keratoses. Treatment tends to be milder but may require a longer duration of therapy.

Different topical medications vary in strength, treatment duration, expected reactions, and effectiveness. Treatment plans are often individualized based on the location and severity of sun damage.

Photodynamic Therapy

Photodynamic therapy (PDT), sometimes called “blue light treatment,” is another option for treating widespread actinic keratoses and sun damage.

During PDT, a photosensitizing medication is applied to the skin and later activated with a specialized light source. This treatment helps target abnormal sun-damaged cells while treating larger areas of skin at once.

Patients may experience redness, burning, peeling, or temporary sensitivity following treatment, and strict sun avoidance is usually required for a short period afterward.

Why Does the Skin Look Worse Before It Improves?

Topical treatments often make damaged areas more visible before healing occurs. Areas with the greatest sun damage frequently react the most intensely.

After treatment is completed, the skin generally heals gradually over time.

Are These Reactions Normal?

Redness, irritation, crusting, burning, and temporary discomfort are common during treatment. However, patients should still contact their physician if reactions become unusually severe or concerning.

Final Thoughts

Topical treatments can play an important role in managing actinic keratoses and broader sun damage. Because treatment reactions vary from patient to patient, close follow-up, individualized recommendations, skin examinations, and continued sun protection are important.