Lasers, light sources battle acne

June 1, 2006

Used alone or in combination with aminolevulinic acid (ALA), lasers and light sources have shown effectiveness in treating acne, according to an expert.

Used alone or in combination with aminolevulinic acid (ALA), lasers and light sources have shown effectiveness in treating acne, according to an expert.

Lasers and light sources that have been used alone to treat Propionibacterium acnes include blue lights, KTP and pulsed-dye lasers and intense pulsed light (IPL) sources, says Thomas E. Rohrer, M.D., of Skincare Physicians in Chestnut Hill, Mass., and clinical associate professor of dermatology at Boston University.

For example, one study found that treatment with blue light (ClearLight, Lumenis) reduced mean acne lesion count by 60 percent and P. acnes colony count by one to two orders of magnitude (Kawada A et al. J Dermatol Sci. 2002 Nov;30(2):129-135). Similarly, a study of 88 patients treated with ClearTouch (Radiancy), which combines pulsed light and heat, found that this device achieved more than 50 percent reduction in inflammatory lesions in 66 percent of patients (Gregory AN. Cosmetic Derm. 2004;17(5):287-300).

Dr. Rohrer says, "The upside of these treatments is that they are generally fairly quick, painless procedures. The downside is that P. acnes will regenerate itself fairly rapidly, usually within two to three months, so often the acne comes right back."

Among the three modalities, he adds that while none performs head and shoulders above the others, blue light is most efficient, requiring the lowest amounts of energy.

Blue light, KTP, pulsed-dye lasers and IPL devices also can be used in conjunction with ALA (Levulan, Dusa Pharmaceuticals), Dr. Rohrer points out.

"When one adds ALA to the mix, the ALA is somewhat preferentially absorbed by the sebaceous glands. Then, when one activates it with a variety of different light wavelengths, one gets a form of photodynamic excitation where it damages the sebaceous gland and potentially alters the tubule that drains it," he explains. Adding ALA helps to achieve long-term improvements in acne, with some studies showing up to 1.5 years, Dr. Rohrer adds.

TRICKS TO EFFECTIVE TECHNIQUE

Procedurally, Dr. Rohrer says, "The trick is getting decent absorption into the skin."

To that end, he says one can use a variety of cleaners such as alcohol, acetone or even microdermabrasion. Next, he advises leaving the ALA on for 45 minutes to 60 minutes before treating with the light source.

Dr. Rohrer adds, "One must also make sure that patients don't go out in the sun for 48 hours afterwards. The problem with photodynamic therapy (using ALA) is that some people have a photo-toxic reaction" that includes intense redness, swelling and sometimes crusting.

A variety of infrared lasers including the SmoothBeam (Candela), CoolTouch (CoolTouch) and Aramis (Quantel Medical) also are used to treat acne, Dr. Rohrer says.

"These lasers heat the superficial dermis. And although they're not selectively heating the sebaceous glands, these glands reside in the upper dermis and are somewhat heat sensitive," he says.

Therefore, Dr. Rohrer says that when one heats the superficial dermis, changes are produces including decreased sebaceous gland size (Paithankar DY et al. Lasers Surg Med. 2002;31(2):106-114), (Friedman PM et al. Dermatol Surg. 2004 Feb;30(2 Pt 1):147-151) that may straighten the tubule that drains the gland.