Cryotherapy is frequently used for one or several clearly defined actinic keratoses. During treatment, Dr. Thomas Knackstedt applies liquid nitrogen to freeze and destroy the abnormal cells. The procedure is performed during an office visit and generally takes only a few moments per lesion.

The treated area may become red, swollen, or blistered before forming a crust. Healing commonly takes one to several weeks, depending on the location and intensity of treatment. Temporary lightening or darkening of the skin can occur, and repeat treatment may be necessary for thicker or persistent lesions. Cryotherapy treats individual visible spots but does not address the entire surrounding field of sun damage.

Topical medications are considered field treatments because they can treat both visible AKs and surrounding areas containing microscopic sun-damaged cells.

Fluorouracil

Fluorouracil, often called 5-FU, interferes with the growth of abnormal skin cells. It is typically applied once or twice daily for several weeks, depending on the product, location, and treatment plan.

During therapy, the treated skin usually becomes red, inflamed, crusted, and tender. This reaction can be noticeable, but it is an expected part of treatment. After the medication is stopped, the skin gradually heals and becomes smoother. Fluorouracil should not be used during pregnancy.

Imiquimod

Imiquimod stimulates the skin’s immune response to recognize and clear abnormal cells. Several strengths and dosing schedules are available, ranging from shorter cycles to courses lasting several months.

Redness, scaling, crusting, tenderness, and occasional flu-like symptoms may occur. Board-certified dermatologist Dr. Thomas Knackstedt may adjust the treatment frequency or recommend a brief rest period if the reaction becomes excessive.

Diclofenac Gel

Topical diclofenac is an anti-inflammatory medication used over a broader area of sun-damaged skin. It generally produces a milder reaction than fluorouracil but requires a longer treatment course, often two to three months.

Patients may experience redness, dryness, itching, or irritation. Careful sun protection is particularly important while the medication is being used.

Photodynamic therapy, or PDT, is an office-based field treatment that can address numerous actinic keratoses across the face, scalp, or another sun-damaged area.

A photosensitizing medication is applied to the skin and allowed time to absorb into abnormal cells. The area is then exposed to a controlled light source that activates the medication and destroys the targeted cells.

Patients may feel burning, stinging, or warmth during illumination. Redness, swelling, peeling, and crusting can follow. Because the skin remains extremely light-sensitive after treatment, patients must follow strict light-avoidance instructions, commonly for approximately 48 hours. More than one session may be recommended.

A medical-grade chemical peel can treat a broader field of actinic keratoses and sun damage by creating a controlled removal of damaged surface layers. This is different from a light cosmetic peel or an at-home product.

Following treatment, the skin may become red, swollen, sore, and visibly peel as new skin develops. The depth of the peel and expected recovery vary by the treated area and the chemical formulation selected. Medical chemical peels require careful patient selection and should be performed under appropriate dermatologic supervision