What it is

→ Field therapy with 5-FU (5-fluorouracil) is a topical dermatological treatment used to target areas of skin that have developed actinic keratoses (precancerous lesions caused by chronic sun exposure) and other forms of actinic damage.

→ Instead of treating a single lesion, field therapy addresses an entire “field” of sun-damaged skin (such as the face, scalp, forearms, or chest), where both visible and hidden (subclinical) lesions may exist.

→ 5-FU is a chemotherapeutic cream that works by selectively destroying abnormal, sun-damaged skin cells while sparing most normal skin.

→ The goal is to clear existing precancerous lesions, reduce the risk of progression to skin cancer, and rejuvenate the skin’s surface.

Why it’s done

→ Field therapy with 5-FU is performed to:

• Treat multiple actinic keratoses across a large sun-exposed area.
• Target both visible and invisible lesions, preventing future cancers.
• Reduce the risk of squamous cell carcinoma.
• Improve cosmetic appearance, as treatment often leaves skin smoother and clearer after healing.
• Provide a non-surgical option for patients who have widespread sun damage.

→ It is especially useful for individuals with fair skin, a history of long-term sun exposure, or repeated episodes of actinic keratosis.

Alternatives

→ Alternatives to 5-FU field therapy include:

• Imiquimod cream → stimulates the immune system to attack abnormal cells.
• Diclofenac gel → anti-inflammatory topical therapy, milder but slower-acting.
• Ingenol mebutate → previously used but less common due to side effect concerns.
• Photodynamic therapy (PDT) → light-based treatment that destroys damaged cells with a photosensitizing agent.
• Cryotherapy → liquid nitrogen freezing, usually for isolated lesions, not field-wide areas.
• Laser resurfacing or chemical peels → cosmetic options that also reduce precancerous lesions.

→ Dermatologists may combine these therapies with or alternate them after 5-FU treatment for optimal results.

Preparation

→ Preparing for 5-FU field therapy involves:

• Dermatology consultation → to confirm diagnosis and select the treatment area.
• Avoid sun exposure → skin should not be sunburned or freshly tanned before therapy.
• Stop irritating skincare → discontinue harsh exfoliants or retinoids 3–5 days before starting.
• Plan downtime → treatment often causes redness and peeling, so patients may wish to schedule around work or social events.
• Baseline photos → dermatologists may record images to track progress.
• Moisturizers and sunscreens ready → patients should prepare post-treatment skincare in advance.

How it’s Done

→ The therapy typically follows this process:

• Application → 5-FU cream is applied directly to the affected area once or twice daily, as prescribed.
• Duration → treatment usually lasts 2–4 weeks for facial skin and longer (up to 6–8 weeks) for thicker skin on arms or scalp.
• Reaction phase → within a few days, the treated area becomes red, inflamed, and may blister or peel. This indicates the drug is working on damaged cells.
• Completion → treatment continues until most lesions are destroyed and the dermatologist decides to stop.
• Healing phase → after discontinuation, the skin gradually heals, leaving smoother, healthier skin.

→ Some patients may receive sequential or combination treatments (such as cryotherapy or PDT) after the 5-FU cycle for enhanced clearance.

Recovery

→ Recovery involves a healing period after the treatment cycle:

• Redness, swelling, crusting, and peeling usually peak during treatment.
• Discomfort can be managed with soothing ointments, cool compresses, and mild pain relief if needed.
• Healing phase typically takes 2–4 weeks after treatment stops.
• Skin improvements (smoother texture, clearer tone) appear gradually as healing continues.
• Sun protection is critical during recovery to prevent further damage.

→ Most patients fully recover within 1–2 months, depending on the size of the treatment field.

Complications

→ Common temporary side effects include:

• Redness, irritation, and itching.
• Crusting, scaling, or blistering in the treated area.
• Swelling or discomfort.
• Photosensitivity requiring strict sun protection.

→ Rare but possible complications include:

• Infection if the skin barrier is broken.
• Allergic reactions to the cream.
• Persistent pigmentation changes (lighter or darker spots).
• Scarring (rare if used under medical supervision).

→ Despite these risks, 5-FU is considered highly effective and safe when monitored by a dermatologist.

Treatment options in Korea

→ Korea offers advanced dermatology care, and field therapy with 5-FU is widely practiced for sun-damaged skin and actinic keratoses.

• University hospitals and clinics such as Asan Medical Center, Samsung Medical Center, and Seoul National University Hospital frequently prescribe 5-FU therapy.
• Customized protocols → Korean dermatologists often combine 5-FU with other treatments such as photodynamic therapy, cryotherapy, or laser resurfacing for better results.
• Patient education → Korean clinics emphasize strict sunscreen use and preventive strategies during and after therapy.
• Follow-up programs → patients undergo scheduled monitoring to ensure complete healing and detect recurrence.
• Integration with aesthetics → clinics may include cosmetic dermatology treatments (like chemical peels or skin rejuvenation) alongside field therapy to improve both medical outcomes and appearance.
• Medical tourism services → English-speaking staff and international patient programs make these treatments accessible to visitors seeking advanced care.

→ With cutting-edge dermatology, combination treatment strategies, and strong preventive culture, Korea is an excellent place for managing actinic damage with 5-FU field therapy.