Phototherapy

'Blue' and red light

It has long been known that short term improvement can be achieved with sunlight. However, studies have shown that sunlight worsens acne long-term[citation needed]. 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%;[28] 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.[29] Particularly when applied over several days, these free radicals ultimately kill the bacteria.[30] 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.[31] 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;[32] 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 to buy initially, although the total cost of ownership can be similar to many other treatment methods (such as the total cost of benzoyl peroxide, moisturiser, washes) over a couple of years of use.

Photodynamic therapy

In addition, basic science and clinical work by dermatologists Yoram Harth and Alan Shalita and others has produced evidence that intense blue/violet light (405-425 nanometer) can decrease the number of inflammatory acne lesion by 60-70% in 4 weeks of therapy, particularly when the P.acnes is pretreated with delta-aminolevulinic acid (ALA), which increases the production of porphyrins. However this photodynamic therapy is controversial and apparently not published in a peer reviewed journal.

Laser treatment

Laser surgery has been in use for some time to reduce the scars left behind by acne, but research has been done on lasers for prevention of acne formation itself. The laser is used to produce one of the following effects:to burn away the follicle sac from which the hair growsto burn away the sebaceous gland which produces the oilto induce formation of oxygen in the bacteria, killing themSince lasers and intense pulsed light sources cause thermal damage to the skin, there are concerns that laser or intense pulsed light treatments for acne will induce hyperpigmented macules (spots) or cause long-term dryness of the skin.In the United States, the FDA has approved several companies, such as Candela Corp., to use a cosmetic laser for the treatment of acne. However, efficacy studies have used very small sample sizes (fewer than 100 subjects) for periods of six months or less, and have shown contradictory results.[33] Also, laser treatment being relatively new, protocols remain subject to experimentation and revision,[34] and treatment can be quite expensive. Also, some Smoothbeam laser devices had to be recalled due to coolant failure, which resulted in painful burn injuries to patients.[