What is Ultra Violet Light (UV)?

What is Ultra Violet Light (UV)?

Ultra violet light is a form of invisible light, and it is so named because it has a frequency higher than the violet component of visible light. A higher frequency means that the rays have higher energy and a shorter wavelength. That is why it is sometimes called short wave radiation.

UV light can be divided into many subtypes depending upon wavelength (or frequency). Following are the more common types

UVA (Wavelength 400-315 nm)

It is the most abundant and the least harmful to human health. The tanning effect of sunlight is mostly because of UVA.

UVB (Wavelength 315-280 nm)

The proportion of UVB in natural sunlight is very low. It has a higher energy and can hence bring about dramatic changes to human skin, and it has a higher potential of damaging the skin by the same token.

Other Types

Many other types can also be enumerated like UVC, VUV (Vacuum UV) EUV (Extreme UV) etc.

What is the role of UV light in treatment of Vitiligo?

Both UVA and UVB are used in the treatment of Vitiligo as well as many other skin disorders. Both can however cause skin burns and local reaction, but many believe UVB to be a potential hazard for skin cancer.

PUVA

Many skin Diseases like psoriasis, eczema and vitiligo are treated with variable success by making the skin extra sensitive to light with the help of psoralens (oral / topical), and then exposing to UVA light. The procedure must be carried out under strict medical supervision.

Narrow band UVB Treatment

Exposing the skin to UVB light, especially the 310 nm narrowband has been found quite promising in the long term management of a number of skin diseases like psoriasis, eczema, vitiligo, and others. Sensitization of skin with psoralens is not usually required.