The Phototherapy or Light Therapy and Acne
Light therapy consists of exposure to specific wavelengths of light using LEDs, fluorescent or dichroic lamps or very bright, full-spectrum light for a specific amount of time.
Light therapy proved to be effective in treating acne, as well as other disorders related to skin and not only. We shall limit to acne during this article and talk a little bit more about light therapy’s results in treating other diseases in a further article.
When limited to acne one can speak about blue or red light therapy.
This new method of treating acne gets its root in a very old belief that sunlight improves acne. Sunlight was thought to be good in treating acne due to its antibacterial and the other similar effects of the ultraviolet spectrum. On the other hand, sunlight can never be used as a treatment because its long-term skin damage.
So, it was found out that some of the visible violet light that is also present in sunlight, in the range 405-420 nm activates porphyrin (Coproporphyrin III) in Propionibacterium acnes that damages and eventually destroys the bacteria by releasing nothing else than singlet oxygen. A total of 320 J/square cm of light within this range renders the bacteria non viable.
This part of the light spectrum is found just outside the ultraviolet range and produces little if any tanning or sunburn.
If applied for three consecutive days, it seems that this light is able of reducing the bacteria in the skin’s pores by 99.9%.
Since people normally have few porphyrins in their skin, this treatment is believed to be safe, excepting obviously the cases of patients with porphyria. However, eye protection is strictly needed while being treated with this light, because of the light sensitive chemicals in the retina.
The light for this treatment is usually created by fluorescent lamps, or bright LEDs or dichroic filament bulbs.
The treatment with this light is often mixed with application of red light, which has been shown to activate ATP in human skin cells (this is essentially a photobiomodulation effect), and seems to improve response rates to the treatment.
Overall improvements of an average 80% of acne sufferers that tried this treatment over 3 month showed that this method performs better than Benzoyl peroxide, with treatment being also far better tolerated.
Home use light boxes usually work well and they are effective for people with long-term acne. These home tools are likely to be cheaper than dermatologist office light treatments, and can be repeated over several years for negligible cost, as opposed to once weekly or fortnightly.
However, the strength of light at a dermatologist clinic is likely to be of a much higher strength, possibly negating the disadvantage of not being used so often, the most prominent model of which is Omnilux. As of 2007 even though they are not cheap, the cost is on a par with the total cost of benzoyl peroxide, moisturizer and facial washes over the total life of the light box, and the light boxes may yet get cheaper due to economies of scale.
On the other hand, application in a dermatologist’s office is usually much more costly, and not necessarily any more effective, but the visible blue light is sometimes used with off-label use of aminolevulinic acid; this causes the bacteria to generate more than normal quantities of porphyrins and this greatly improves response. Whilst temporary redness and edema is experienced, this can give over a year of clearance with just a few applications.
There is some skepticism and lack of data over some of the treatments of acne vulgaris through visible light, which is something that is mainly characterizing all the newer and relatively experimental photodynamic treatments.