Dermatology – UVA1 Phototherapy
I hope yesterday’s post didn’t fall into the realm of TMI. Today should be better.
Pictured left is the Daavlin ML24000 UVA1 unit I’ve been using at Johns Hopkins. Click on the photo to enlarge or the link to see the manufacturer’s description. The four light towers alternate with open space. There are hand grasps – circular bars in the ceiling and vertical bars in the side openings – to help expose hard to reach areas. Each tower contains six UVA1 spectrum light bulbs backed by reflectors to diffuse the light more evenly. Because the lights generate a lot of heat, a stong fan circulates cool air around the inside of the booth. If I close my eyes, there’s the sensation of standing in the hot sun with a stiff, cool breeze. Aside from the noisy fans, it feels quite pleasant. The phototherapy nurse, Tracey, said I could bring music with headphones to block the noise; however, to avoid holding my phone or iPod, it seems like I’d need a long wire from the headphones to leave the source outside on the chair – there are no pockets or places to clip a phone when you’re naked. Seems like too much trouble for the short time I’m in there. So far, the fan hasn’t really bothered me. Because of the green goggles, everything has a rather eerie green glow except that the blacklight effect makes my fingernails and toenails glow bright white.
A curtain, pictured below, surrounds the booth and chair for privacy. Each session, I undress completely, don my goggles, enter the machine, and yell to Tracey that I’m ready. She sets the timers and turns on the machine. The lights shut off automatically after the set time but the fan keeps running. I learned after the first time to jump out as soon as the lights go off. Otherwise, it’s cold!
Before my first treatment, Tracey examined me to establish my baseline. She’ll check again tomorrow before my 4th treatment to assure I’m having no adverse effects. It usually takes 10 or more treatments to determine if there’s improvement. My planned treatment schedule is as follows:
I chose UVA1 instead of PUVA or extracorporeal photopheresis (ECP) primarily because it’s simple and relatively free of side effects. The photoreactive drug, psoralen, that is required with PUVA therapy is metabolized via the liver and excreted via the kidneys and may cause nausea or an allergic reaction. ECP takes a long time each session to draw the blood, treat it and return it, and I’d probably have needed a port or picc line, a nuisance for maintenance and a potential source of infection. For UVA1, all I have to do is undress and stand in a booth for 11-26 minutes! Besides that, it’s leading edge technology :-).
UVA1 light does not burn but my skin will darken. I don’t mind that at all! Another short term effect is dryness. I need to drink lots of water and use a good moisturizer (without sunscreen). Potential long term side effects are essentially the same as those from exposure to sunlight – increased risk of skin cancers and photoaging. Because I’ve had so little time in the sun over the course of my lifetime, I’m at an advantage in that respect. My former coworkers jokingly called me the cave woman and once presented me with a Fred Flintstone costume at a staff meeting.
After only two treatments, the brown patches on my arms, legs, and abdomen seemed lighter. Michael thought so, too. I had some red bumps inside my right forearm, probably a polymorphic light eruption rash from photosensitivity. They disappeared within a day. My skin overall is very slightly darker, noticeable to me but probably not to others who routinely get more sunlight than I. My back is dry and peeling slightly but otherwise unchanged. The most dramatic change I noticed, which may or may not have anything to do with the phototherapy, was a reduction in my overall aches and pains. Tracey said it’s too soon for any discernible results but maybe I’m atypical in a good way this time. Fingers crossed!
General UVA1 Information
UV refers to light energy in a range between visible light and x-rays and has three subranges:
Sunlight contains UVA, UVB, and UVC. We aren’t exposed to UVC because it’s absorbed by the ozone layer. The UVB rays are absorbed by the outermost layer of skin, the epidermis, and don’t penetrate deeply. They cause sunburn. UVA rays penetrate more deeply and cause tanning as well as aging and carcinogenic effects. Both UVA and UVB rays can be therapeutic for skin conditions because of their effect on the different types of cells, particularly certain T-cells. UVA rays are useful in treating sclerotic conditions but don’t penetrate deeply enough to be effective without the assistance of a photoreactive drug like psoralen. UVA1 light, in the range 340-400nm, has the shorter wavelengths removed and thus penetrates deeper without the drug. It is also believed to affect different cells than UVA. More research is needed to completely understand why and how the various light therapies work.
UVA1 treatment originated in Germany around 1997 and is still more widely used in Europe than here. The United States didn’t start treating with UVA1 until about 2003. Other parts of the world use higher doses than the US.
The highest dose given at Johns Hopkins is 70 J/cm2, while doses of 130 J/cm2 are routinely given in Europe and New Zealand.
I’ve linked a couple of interesting articles under “Other useful info…” on the left sidebar in case you’d like more detailed information.