Northern Phototherapy Mgmt Facility

The discovery and history of uvb light 

Virtually every creature on this planet owes its existence to the Sun.  Light is necessary to maintain a healthy immune system and metabolism, but you can easily get burned if you stay out too long.  As a result, all creatures have developed various ways of regulating their exposure to the Sun; in humans it's called "tanning".

Your skin is a remarkably complex organ.  It constantly replaces old cells with newer ones at a fairly even pace; normally you shed about as many cells as you make. The new skin cells look just like the old skin, but it's not the same. As with all organs, things can often go wrong as with psoriasis and vitiligo.  These conditions, and several other related skin ailments, are thought to be influenced or caused by a faulty or weak immune system.  Let's look at psoriasis specifically, as there is a much longer history of treating psoriasis.

Regions where people spend little time outside in the sun have a higher incidence of psoriasis than those who spend a lot of time outdoors; this usually coincides with a warmer climate, so the closer you get to the poles, the bigger the problem becomes. This is not to say that people living in colder locales have more psoriasis than those in warmer latitudes, only that the condition can be kept in control with enough sunlight. Many people don't even realize they have psoriasis until they start spending more time inside or where there's less light. Others who've had psoriasis for years improved in the summer and became much worse in the winter, but there wasn't much that anyone knew that would help.

When doctors began to notice that most people with problem psoriasis improved by spending more time outside, they also began to notice that people who spent time outside at the Dead Sea got even better, and it lasted longer. For thousands of years people suffering with psoriasis have sought relief by visiting the Dead Sea, often on a regular basis.

 Much of the light produced by today's fluorescent lamp is filtered by the inner coating of the bulb. By varying the coating, they found that they could make lamps that simulated real sunlight to the extent that they could use them to grow plants; these are what we call 'full-spectrum' lamps, and they emit much more ultraviolet light, which is what the plants seemed to need. They were also found to be capable of generating a suntan and were quickly used in the earliest tanning systems, and it didn't take long before doctors were using them to treat skin conditions.

The lamp manufacturers then began to develop lamps specifically for tanning that produced more ultraviolet than normal office lamps, but not as much as the grow lights. By splitting the ultraviolet light spectrum into three subdivisions - UVA, UVB & UVC - they began to discover that there were many medical uses for these lamps. The first tanning lamps produced UV light in both the UVA band (which stimulates the skin into tanning) and the UVB band (which causes sunburns). Many psoriasis patients found relief by visiting tanning salons, but that became less and less effective as the UVB rays were all but eliminated from modern tanning lamps. Without the UVB light the psoriasis was unaffected, although they usually did get a tan.

Back in the 1920's, the medical world first began to seriously look at phototherapy for a variety of ailments. Psoriasis was found to respond well to brief but regular exposures to UVB light (what we now call 'broadband UVB'); not enough to produce a sunburn, but enough to hold the psoriasis at bay. This became a very reliable and relatively safe treatment for the vast majority of people suffering with psoriasis, but people still swore by their treatments at the Dead Sea. There seemed to be something unique about that specific location that produced better results for more people, but they didn't know if it was the air or the water or the salts or something else that was making a difference for so many people.

In order to determine if this was factual or not, light measurements were taken at the Dead Sea and it was found that a combination of the low altitude (the Dead Sea being the lowest point on the Earth's surface), the high humidity and the Equatorial location, there were larger amounts of UVB light within a very specific range than anywhere else they had measured. This narrow band of light, between 308 and 313 nanometers, was found to be what the skin was 'thirsty' for, and was eventually duplicated.

These new lamps (Narrow Band UVB, or NB-UVB) were developed specifically for medical use and were found to produce faster and better results than the broadband UVB lamps. What's more, it appears that vitiligo is just as 'thirsty' for NB-UVB as psoriasis, and sufferers of both conditions finally had some hope of regaining their normal looking skin by simply exposing their skin to these lamps, rather than taking oral medications that seemed to help but were very stressful on the internal organs.   Since UVB treatments were started at the Mayo Clinic in 1926, there is nothing in the medical literature showing that proper use of UVB has ever caused an increased risk of skin cancer.

NB-UVB treatment can be used by adults and children, and will be effective in treating psoriasis for the majority of patients who meet these criteria:

• Thin to moderate plaques
• Moderate to severe (involving more than 3 percent of the skin)
• Responds to natural sunlight