We’ve already mentioned above a few possible short term side effects during light treatment for skin. Overuse of narrowband can result in burning, just like sunlight and broadband UVB. Frequent emollients or moisturisers can be applied, and if recommended by the doctor, topical steroids. It is important that if you use ointments in conjunction with Narrowband UVB treatment, that the ointments should be applied after the treatment, unless you have been advised otherwise by your doctor or dermatologist. UVB sometimes provokes polymorphous light eruption. Long term exposure to ultraviolet radiation ultimately causes skin ageing and skin cancers.
If used sensibly Philips Narrowband is certainly less risky than Broadband and PUVA treatment because most of the UVB narrow band light therapy is within the therapeutic wavelength of 311nm, Broadband light is over a much wider wavelength – less UVB in total (and much less within the therapeutic wavelength) and a greater percentage of UVA. Cheaper narrowband tubes will also emit less light at 311nm and more in the non-therapeutic wavelength – hence increasing your chances of short term and long term problems.
More generally, you must remember that all UV radiation can cause skin damage and light treatment for psoriasis, vitiligo and other skin conditions have to be rationed. Doctors will not put patients at unnecessary risk and care should be taken with the number of treatments over one year and indeed over a lifetime. This will vary from person to person depending on skin type and total dose administered.
This is why, once your condition has improved significantly do not use the unit again until you feel the ailment returning or your condition worsening (this could be after several weeks or months and in some cases over 12 months – everyone is different), then just a few sessions are usually required to keep it under control again. Do must not use the unit continuously, if you do you may increase the risks of long term skin problems !