Laser therapy aims to prevent run-of-the-mill "zits" (papules and pustules), and appears to be less effective with non-inflammatory acne (whiteheads and blackheads) and severe lesions (cysts and nodules).1 Lasers, much like at-home light devices, work on the premise of exciting compounds called porphyrins, which live inside acne bacteria.2 When the lasers excite the porphyrins, the porphyrins damage the bacteria wall, effectively killing the bacteria.3 Less acne bacteria should help reduce symptoms of acne. Laser treatment requires trips to the doctor's office, and costs $200-$500 per treatment. Doctors usually recommend three treatments, about a month apart, though some doctors recommend more treatments, and sometimes more frequently. The kinds of lasers that doctors use on acne patients include Diode, Pulsed Dye, Fractional, KTP, InfraRed, and Pulsed Light and Heat Energy (LHE), as well as a new "vacuum" laser called Isolaz.4-5 Doctors sometimes apply ALA (5-aminolevulinic acid) prior to laser treatment. ALA makes the skin more sensitive to light, and may help produce more porphyrins within bacteria.1,6-7
Several studies attempting to gauge laser effectiveness exist. However, these studies are almost all small cohort (just a few people), often lack split face design (compare one side of the face to the other), tend to lack long follow up (so it's hard to tell if results last), and often employ no controls. Still, almost all of the studies show at least some improvement in acne symptoms. Consensus amongst researchers is that results are temporary since colonies of acne bacteria grow back quickly. Results are also incomplete, meaning lasers alone usually do not completely clear acne. The studies show anywhere from 37% clearance to 83%.2,8-11
Some patients experience pain during treatment. Most people report redness after treatment as well as some inflammation and skin peeling. ALA treatment may cause skin darkening and/or folliculitis (inflammation of hair follicles), and requires absolute avoidance of sunlight for 30 hours after treatment to minimize such effects.10
At this time, it's hard to say whether lasers are worth the time and effort, and if so, which lasers are best. A systematic review of the 19 avaialable controlled studies on lasers and acne, published in The Journal of the European Academy of Dermatology and Venereology, concluded "...most of the studies were of suboptimal methodological quality...we conclude that optical treatments with lasers...possess the potential to improve inflammatory acne on a short-term basis...optical treatments for acne today are not included among first-line treatments."11 Since insurance rarely if ever covers such procedures, patients need to weigh the cost/benefit ratio. Both proper topical treatment, as well as isotretinoin (Accutane) for people with severe acne, can provide more predictable, consistent, and complete clearing.
When you delve deeply into literature on lasers and acne, you find one study where researchers combined long duration ALA exposure with intense laser therapy.12 Results from this study points toward potential long term damage to sebaceous (oil) glands. Since acne cannot exist without sebaceous glands, this research is intriguing. Unfortunately, most patients in these trials experienced skin darkening and/or folliculitis. Still, this is an area well worth further investigation.