Depigmentation Therapy in Extensive Vitiligo – Safe or Not

If vitiligo has affected 50% (or more) area of the body, depigmentation therapy can be considered as an option. The method reduces the skin color of unaffected skin by applying strong topical lotions or ointments. The objective is to impart an even skin tone. Though treatment is permanent, it can make the skin more fragile or sensitive to sun exposure.

To complete the transition, typically a bleaching solution is applied daily for up to 12 months. It typically takes 2 or 3 months before an individual see any effects. Speaking of effectiveness, about 95% of people usually experience depigmented skin.

At present, no ideal depigmenting therapy is available, yet many agents and laser therapies have been in use for many years. The most popular skin lightening chemicals that are used in both prescription and over-the-counter products are Monobenzyl ether of hydroquinone (MBEH), 4-methoxyphenol, and 88% phenol. Among these MBEH is FDA approved in the USA but takes many months to depigment. Physical therapies for depigmentation include the Q-switched ruby and alexandrite lasers and cryotherapy.

Advantages of depigmentation therapy for vitiligo

• • Even tone skin color

• • Improved self-esteem
  • Better self-image

• • A topical depigmenting agent like MBEH has antioxidant properties.

Disadvantages of depigmentation therapy for vitiligo

• • • The treatment is rarely used as the skin without pigment is very vulnerable to damage from sun exposure.
    • About 50% of people experience side effects (especially on the face) such as skin redness, dryness, itching, and burning.

How does de-pigmentation therapy work?

Topical depigmenting agents or laser is used to lighten the skin tone for those who have vitiligo or similar conditions. The effect is to lessen the amount of melanin (or work in different ways to inhibit melanogenesis – the pigmentation pathway by which cells produce melanin) that is still present in the areas unaffected by vitiligo, thus providing a more even appearance to the skin.

Topical Depigmenting agents

Topical Depigmenting agents used in extensive vitiligo have been shown to easily prevent melanin production in the skin where melanocytes are still fully functional. Mostly prescribed topical depigmenting agents include:

Monobenzyl ether of hydroquinone (MBEH)

Mechanism of action: It induces cellular oxidative stress in exposed pigmented cells by producing peroxide.

Treatment procedure: The process can be carried out from the comfort of one’s home. First, an open use test should be performed on the forearm (pigmented area). If no contact dermatitis develops, the cream can be applied to the face or areas chosen as the top priority. Gradually, lightening of the skin occurs over a period of 4 to 12 months.

Side effects: Mild burning or itching, irregular leukoderma, contact dermatitis, ochronosis, and risk of carcinogenesis. Protection from sunlight is necessary as repigmentation risk is high.

4-methoxyphenol (4-MP)

Treatment procedure: The tropical agent can be used in 20% concentration in an oil/water cream base. Patients should be instructed to test the cream on a normal pigmented spot (as big as 5 cm) to observe an allergic reaction within 48 hours. Patients with a negative allergic reaction are allowed to apply the cream on the remaining pigmented skin areas twice a day until complete depigmentation is observed. The longer the cream is used, the better the results.

Side effects: Mild burning or itching, irregular leukoderma, contact dermatitis, ochronosis, and risk of carcinogenesis. Protection from sunlight is necessary as repigmentation risk is high.

Phenol

Treatment procedure: Before the application, the skin is cleaned with soaked with alcohol. A swab moistened with phenol is used to treat small areas until cutaneous frosting occurs. Initially, the patient feels a burning sensation for approximately 60 seconds, which should gradually decrease in intensity.

Post-procedure care: Delicate cleaning with saline, use of antibiotic ointment with steroids of mild to moderate potency and sun blocks should be done.

Side effects: Non-aesthetic scar formation, dyschromia, and development of herpetic eczema, repigmentation if exposed to ultraviolet radiation.

Physical therapies for depigmentation

Lasers can be used in cases when bleaching agents fail. It is ideal for areas like face where rapid depigmentation is required within days. Lasers also overcome the disadvantages of topical agents (local redness, burning, itching). Unlike topical therapy, Lasers don’t take a long time of 10 months to depigment. Depigmentation through laser is an effective, fast, and safe method with reduced chances of repigmentation. Frequently used Physical therapies for depigmentation include:

Q-switched ruby (QSR) laser (694 nm)

Advantages: Depigmentation is rapid and occurs in 1 to 2 weeks.

Mechanism of action: The QSR lasers induce selective photothermolysis of pigmented lesions, which are absorbed easily by melanin.

Q-switched alexandrite laser (755 nm)

Advantage: It has a faster pulse frequency, which allows for more rapid therapy. Additionally, it also has a higher wavelength, which facilitates greater tissue penetration and improves results.

Disadvantages: The local anesthesia is required as the procedure is painful. Since treatment is only possible in a healthcare facility, it becomes an expensive therapy. Also, patients with active vitiligo may respond better to laser therapy than those with stable patches.

Cryotherapy

Advantage: When rapid depigmentation is desirable, it can depigment MBEH-resistant skin. The procedure requires no anesthesia, dressing, sedatives or antibiotics. Preparation time is short. The risk of infection is low and wound care is minimal. The method is simple, easy to perform, safe, efficacious, and cost-effective.

Disadvantages: A qualified, experienced person is required for this hospital-based treatment. Also, cryotherapy is only suitable for small lesions and cannot be done in single seating for extensive depigmentation, unlike lasers. Immediate side effects include edema, pain, and bullae formation. If cryotherapy is performed aggressively, it can lead to permanent scarring.

Precautions

• • Candidates for depigmentation therapy should be carefully screened and educated. Various aspects of this therapy such as the cost, treatment time, probable permanency of depigmentation, side effects, and the possibility of repigmentation should first be discussed first. An individual must be provided enough time and assistance in making the decision. Family members should be involved in the process too. It is also important to make the patient understand the cultural effects of depigmentation, (especially in those with dark skin).

• • Mercury should not be used for lightening the screen. The toxic substance is already banned in the United States as it can have severe ill health effects leading to both physical and mental problems.

• • Only those with extensive vitiligo who have failed to respond to medical therapy should consider depigmentation therapy.

• • The therapy should be avoided in children less than 12 years of age.

• • Daily use of sunscreens with or more throughout the year is essential to prevent re-pigmentation as well as sunburn reactions.
  • Avoid application of MBEH to the eyelids and areas close to the eye. After application of MBEH, close skin-to-skin contact with another person should be avoided as it can cause a decrease in pigmentation at the site of contact in the other person.

• • Like treatments for repigmentation, depigmentation therapy requires patience and consistency. The process can take up to 2 years, depending on the amount of remaining pigmentation and the strength of the medication used.