Though there is no cure for vitiligo, there are many effective treatment options for vitiligo. The most effective and best treatment is the combination of psoralen group of medications or their derivatives with ultraviolet rays. This is known as the PUVA or photochemotherapy. Photochemotherapy gives the best repigmentation of the skin turned white by vitiligo.
How Does PUVA Therapy Help Repigment the Vitiligo Skin?
Psoralens sensitize the skin to the ultraviolet rays. The ultraviolet rays act on the melanocytes in the normal pigmented skin and hair bulbs in and around the vitiligo patches and stimulate the melanin pigment to seep into the epidermal cells. The number of melanocytes is also seen to increase in the repigmenting patches. The repigmentation is evident as brown-black dots that appear within the vitiligo patch, which then gradually enlarge to cover the whole area.
Can PUVA Therapy be Given in all Skin Types?
No, it is not advisable for persons with fair skin (skin types 1 and 2) to opt for the PUVA therapy. The danger of skin cancer limits the use of photochemotherapy in these groups. Luckily, risk of skin cancer is very low in skin turned white due to vitiligo; the exact cause is not known for this phenomenon. Sunburn is quite common in vitiligo affected white skin, though.
Is PUVA Therapy Advisable in Children With Vitiligo?
The oral psoralens should not be used in children below the age of 12 years. Topical psoralens may be used at weekly twice intervals in children above the age of 6 years.
When is Topical Psoralens Preferred Over the Oral Psoralens in Vitiligo?
Topical psoralens are preferred in children between the age of 6 to 12 years and in localized vitiligo limited to a small area on the skin and in vitiligo limited to the palms and soles.
How is Topical Photochemotherapy or PUVA Carried Out in Vitiligo?
8-methoxy psoralen or methoxsalen 0.1% lotion or solution is used in topical photochemotherapy . The lotion is applied to the involved area 30 minutes prior to the UVA exposure. The UVA is given at a dose of 0.05 to 0.25 Jules per cm2 in a PUVA chamber at the dermatologists’ office once or twice a week. The dose is adjusted as the minimal erythema dose (MED), meaning the light exposure should be stopped when the white skin turns red. Over exposure will result in burns. The topical psoralen solution should be washed off after UVA exposure to avoid unwanted sun burns and phototoxic reactions.
What is Topical PUVASol Therapy in Vitiligo?
For those who find it difficult to visit the clinic for UVA exposure or for those who cannot afford it, exposure to sunlight is given instead. This is known as PUVASol (Sol for Solar) therapy. The danger of sun burn is real in this case. Hence, depending upon the area involved, skin sensitivity and the temperate zones, the psoralen lotion is diluted either with normal saline or coconut oil ( a dilution of 4 drops of oil to 1 drop of psoralen solution is preferred). The best time for sun exposure is between 11 am to 1 pm. Exposure time is until the skin turns pink. In summer time, an exposure for just 15 seconds may suffice to produce the erythema.
How is the Oral or Systemic PUVA Therapy Carried Out in Vitiligo?
In oral PUVA therapy, 8-MOP is taken orally at a dose of 0.3 to 0.6mg per kg body weight as a single dose two hours before UVA exposure. The initial UVA dosage is 1 to 1.5 J per cm2, gradually increased to 9 J/cm2. The treatment is carried out on alternate days or weekly twice, never on consecutive days. Direct sunlight (PUVASol) is also used instead of UVA depending upon the patient compliance. In those patients with generalized vitiligo who cannot tolerate 8-MOP, 5-MOP or topical 8-MOP bath can be used. In such patients and in children where psoralens cannot be used, narrow band UVB exposure is effective.
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Related Reading
Reference
- Various Journals and Text Books of Dermatology
Disclaimer
The information given in this article is for educational purpose only so that patients are aware of the options available. No diagnosis should be made or treatment undertaken without first consulting your doctor. If you do so, the author or suite101 will not be responsible for any consequences. The images provided are for illustration purpose only.
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