Ultraviolet Light Therapy
Ultraviolet light therapy (UV light) produces an immunomodulatory effect on the skin and is widely used for the treatment of psoriasis, eczema and other conditions. UV light is important for vitamin D synthesis. A variety of reports have suggested that low levels of vitamin D in early pregnancy may be associated with adverse developmental effects. Whether ultraviolet light exposure decreases folic acid levels remains to be studied (Juzeniene 2010).
UV-B light has got a wavelength of 290–320 nm; its effects are confined to the skin and it does not penetrate the uterus. Narrowband UV-B light with a wavelength of 311 nm is less erythemogenic (sunburning potential) than broadband UV-B and since erythema is a risk factor for skin cancer, treatment with narrowband UV-B light should theoretically be less carcinogenic for the same therapeutic results.
UV-A and photochemotherapy
UV-A1 with a wavelength of 340–400 nm penetrates the skin more deeply than UV-B. UV-A1 radiation induces collagenase (matrix metalloproteinase-1) expression, T-cell apoptosis, and depletes Langerhans and mast cells in the dermis. UV-A1 exposure stimulates endothelial cells to undergo neovascularization. UV-A1 exerts significant therapeutic effects in atopic dermatitis and morphea; there is also evidence for its use in other skin diseases, including cutaneous T-cell lymphoma and mastocytosis.
Photochemotherapy (PUVA therapy) combines psoralens with UV-A light to treat, e.g. severe psoriasis and atopic dermatitis. The psoralen makes the skin more sensitive to UV light. PUVA therapy is given either orally or by external application of methoxsalen (8-methoxypsoralen followed by UV-A irradiation). A form of external use is the so-called bath-PUVA, through which the skin is sensitized with the psoralen-containing bathwater. The psoralen is chemically activated by the UV light, binds more strongly to the DNA and damages the cells.
The European Network of Teratology Information Services (ENTIS) analyzed 41 pregnancies in which systemic PUVA therapy with 8-methoxypsoralen was administered (Garbis 1995). This study (Gunnarskog 1993) found no hint for embryotoxic effects.
The IR unit developed by MSCT Infrared Wraps Inc is light, portable and designed to be worn on a belt. It is powered by a small, rechargeable battery and is claimed to be 99% efficient in converting electricity to IR energy.
It contains an IR-emitting element in a unique design with an IR grid and buzz bars down each side to deliver the electricity, converting it to IR energy at a wavelength of 800 nm to 1200 nm.
The IR output was reliable at 800 nm to 1200 nm of wavelength, and there was an automatic shut-off if the temperature rose to 42°C. This feature was lacking in IR laser units, which therefore could cause thermal injury.