Acne vulgaris and its variants have been distressing adolescents for hundreds of years. The development of therapies such as benzoyl peroxides, topical retinoids and antibiotics has changed the course of acne for many patients, while others suffer a relentless course.
The actual incidence of acne is extremely high, affecting approximately 85 percent of individuals at some point in their lifetime. Though most prevalent during the teenage years, acne can present at any age, and while in most cases it's temporary, it sometimes results in lifetime scarring.
Psychological studies have demonstrated that acne is more than just a cosmetic issue. Clinical depression (as well as other psychiatric disorders, including suicide) has been associated with acne. Traditional therapies are useful, but in many cases they do not result in complete clearance of lesions.
Therapies including extractions, peels and laser and light devices can be useful for those who fail topical therapies. In the past, these treatments were considered mostly for cases not responsive to traditional therapies. With increased efficacy and safety, however, they are being used in combination of prescription topicals, even at the onset of therapy. This column will review the latest research and clinical practices for the treatment of acne with laser and light devices.
Acting on acne
Laser and light devices have been used to treat acne since the early 1990s. Many different wavelengths and devices have been used to suppress the lesions of acne, including sunlight.
Depending on the wavelength and delivery mode of the device, targets include Propionibacterium acnes, the plug within the pore or even the sebaceous gland itself. P. acnes produces porphyrins which, when activated by light, result in killing of the bacteria. Optimal absorption occurs within the blue wavelengths (around 415 nm). Other wavelengths, including red and green, have also been shown to activate these porphyrins.
Both red and green light activate porphyrins less well than blue light. However, due to their longer wavelength, they penetrate deeper into the skin. This deeper penetration may help with targeting deeper aspects of the disease, including inflammation deeper in the skin and possibly portions of the sebaceous gland.
Far longer wavelengths have been used to penetrate deeply to the sebaceous gland, resulting in thermal heating and disruption of gland production. These include the infrared (IR) lasers, light-emitting diodes (LEDs) and intense pulsed light (IPL) devices, as well as radiofrequency (RF) devices. The combination of externally applied porphyrins with light activation results in more impressive results and, in general, a more aggressive treatment than light itself.