Narrow-spectrum UVB

In 1976, Fischer discovered that 313 nm UV can effectively treat psoriasis.

Subsequently, in the study of UVB spectrum and the treatment of psoriasis, it was found that UVB at 290~300nm wavelength only produces skin burns (ie erythema effect and keratinocyte necrosis) without therapeutic effect, but 311nm NB-UVB It produces the best skin treatment without burning.

At present, most hospitals use PUVA technology, which requires simultaneous irradiation of UVA ultraviolet light and oral photosensitive tablets. However, the side effects caused by UVA and the side effects caused by photosensitive tablets are obvious. The narrow-spectrum UVB illuminator solves the problem of excessive UV exposure. Not only can patients fully accept the narrow-spectrum UVB emission of light with a wavelength range of 311-312 nm (this range is the most beneficial part of natural sunlight), while UVB treatment does not require taking other auxiliary drugs to avoid The side effects of the use of photosensitizing drugs in traditional PUVA therapy have made narrow-spectrum UVB increasingly popular among patients and physicians.

Traditional broad-spectrum UVB lamps emit light in the wavelength range of 280-330 nm, and clinical studies have shown that light below 300 nm can cause severe burns and increase the risk of skin cancer. Therefore, the 311 narrow-spectrum UVB emission of the 311-312 nm wavelength range is considered to be the safest and most efficient light.

Plus no need to take medicine, avoiding the side effects of PUVA therapy on the body. These benefits make narrow-wave UVB therapy very popular, even in the home, which is also feasible.

Biological effect

Induced T cell death

Some scholars have allowed psoriasis patients to contrast 311nm NB-UVB and UVB, and found that the number of CD3 cells in the epidermis and dermis of patients after NB-UVB irradiation decreased, which was significantly different from UVB, indicating that NB-UVB was on silver scales. A good effect of the disease is to induce T cell death.

Effects on Langerhans cells

Langerhans cells are important antigen-presenting cells in the skin. The study found that the number of Langerhans cells decreased significantly after 311nm NB-UVB irradiation, inhibiting Langerhans cell-presenting antigen-carrying ability and natural killer cell function, and reducing skin inflammation.

Effect on urinary acid

Urinary acid is the main light receptor in the skin. It is naturally present in trans-urinary acid. NB-UVB increases the cis-urea acid in the skin and leads to a decrease in natural killer cell activity.

Effect on cytokines

NB-UVB can inhibit lymphocyte proliferation, interleukin and interferon decrease, and the down-regulation of these cytokines has an important influence on the occurrence and severity of inflammatory diseases and allergic diseases, respectively.

Effect on melanocytes

NB-UVB has obvious therapeutic effect on vitiligo. It is speculated that a variety of cytokines are produced to stimulate the proliferation of multi-seed dopamine-negative achromatic melanocytes outside the hair follicle, produce melanin and migrate to the pigment-depleted site to cause pigment recovery. At the same time, the immune function of NB-UVB protects the melanocytes that migrate and proliferate from damage.

Erythema effect

The minimum erythema of NB-UVB is about 4 times that of UVB, indicating that NB-UVB is less prone to erythema effect. This feature ensures that a higher dose of radiation can be used during treatment, resulting in better efficacy.