It has long been known that short term improvement can
be achieved with sunlight. However, studies have shown
that sunlight worsens acne long-term, as the skin's
natural reaction is to produce more oils. More
recently, visible light has been successfully employed
to treat acne (Phototherapy)
- in particular intense violet light (405-420nm)
generated by purpose-built fluorescent lighting,
dichroic bulbs,
LEDs or
lasers. Used twice weekly, this has been shown to
reduce the number of acne lesions by about 64%;[19]
and is even more effective when applied daily. The
mechanism appears to be that a
porphyrin (Coproporphyrin III) produced within P.
acnes generates
free radicals when irradiated by 420nm and shorter
wavelengths of light.
Particularly when applied over several days, these free
radicals ultimately kill the bacteria.[21]
Since porphyrins are not otherwise present in skin, and
no UV light is employed, it appears to be safe, and has
been licensed by the
U.S.
FDA.
The treatment apparently works even better if used with
red visible light (660 nanometer) resulting in a 76%
reduction of lesions after 3 months of daily treatment
for 80% of the patients;[23]
and overall clearance was similar or better than benzoyl
peroxide. Unlike most of the other treatments few if any
negative side effects are typically experienced, and the
development of bacterial resistance to the treatment
seems very unlikely. After treatment, clearance can be
longer lived than is typical with topical or oral
antibiotic treatments; several months is not uncommon.
The equipment or treatment, however, is relatively new
and reasonably expensive. The equipment can be found in
dermatologist offices but is moving towards personal
portable devices. There are currently a number of brands
coming out with hand held devices that are more
affordable but not as powerful. From
http://en.wikipedia.org/wiki/Acne_vulgaris#.27Blue.27_and_red_light
Ultraviolet Light, especially the non-burning UVA and UVB longer wavelengths, has become the phototherapy treatment of choice for psoriasis, vitiligo, atopic dermatitis (eczema) and mycosis fungoides (a fungal infection of skin) and also has applications for vitamin D3 photosynthesis in human skin. Our UV lamp emits energy only in these non-burning wavelengths and not in the dangerous UVA short wavelengths.