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Laser, light devices useful in clearing obstinate acne lesions

Discussion in 'Dermatology' started by Egyptian Doctor, Dec 15, 2011.

  1. Egyptian Doctor

    Egyptian Doctor Moderator Verified Doctor

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    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.



    Oral retinoids have proven to be an important alternative for those who fail traditional therapies. Many patients find the side effect profile unacceptable, however, and continue to look for safe and effective nonsystemic alternatives.

    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.


    Spotlight on PDT



    Photodynamic therapy (PDT) has been shown to be a safe, reliable and effective treatment for acne. The ideal protocol and regimen for these treatments has been less well accepted, however. Variables to PDT include choice of photosensitizer, incubation time, skin preparation for activation, activation light source and duration.



    Several studies have shown that IPL plus photosensitizer — aminolevulinic acid (AMA) or methyl aminolevulinate (MAL) — performs much better than IPL alone. These studies examined inflammatory and noninflammatory lesion counts and found that the addition of photosensitizer resulted in a further reduction in both inflammatory and noninflammatory lesion counts. The photosensitizer group also experienced more crusting, pain and downtime associated with the procedure. ALA and MAL have been shown to be equivalent in acne (Hörfelt C, Funk J, Frohm-Nilsson M, et al. Br J Dermatol.
    2006;155 .


    Incubation times with PDT have also been examined. Traditional incubation times for treatment of acne have been 30 minutes to one hour. In 2009, Oh et al compared a 30-minute incubation time with a three-hour incubation time using ALA plus IPL. They found that the three-hour incubation time resulted in a further reduction in inflammatory lesion count than did IPL alone or IPL plus 30-minute ALA. This study was performed on Asian skin, so its application to other skin types would need to be studied. (Oh SH, Ryu DJ, Han EC, et al. Dermatol Surg. 2009;35.

    There has been some suggestion that PDT activation of ALA with IPL (580 nm to 980 nm) is more effective than activation with blue light (415 nm)(Taub AF. J Drugs Dermatol. 2007;6. Most likely, this would be due to the effect of the longer-wavelength IPL light on the deeper structures, such as the sebaceous gland.



    Other light sources have also been used to activate ALA or MAL. Activation with the pulsed dye lasers results in improvement in erythematous scarring and temporary improvement with inflammatory lesions, but not the other lesions of acne (Orringer JS, Sachs DL, Bailey E, et al. J Cosmet Dermatol.

    2010;9. Yellow light (585 nm, 595 nm) is not a strong activator of porphyrins; hence the poor response to this source.


    Pretreatment, prior to activation, may also be a method of enhancing results with PDT. Barolet and Boucher used IR LED (970 nm) for 15 minutes prior to PDT. Their study revealed a statistically significant difference between the IR-pretreated side versus the PDT-alone side (73 versus 38 percent). This added benefit of pretreatment with IR may be due to the light or solely to heating.


    Lasers alone



    Side effects, downtime and the need to avoid light post-treatment sometimes preclude PDT treatments in teenagers. In these cases, lasers alone (most with less downtime than PDT) can be used to treat acne.



    Two split-face trials with the 532 nm KTP laser showed conflicting results. One study showed no benefit, while the other showed a 35 percent reduction in lesion count on the treated side (Bowes LE, Manstein D, Anderson RR. Lasers Med Sci. 2003;18 .



    The 1,450 nm diode laser has better-documented reduction rates than the KTP, including a 75 percent decrease in lesion count compared to the control side (Jih MH, Friedman PM, Goldberg LH, et al. J Am Acad Dermatol. 2006;55 ). This diode laser requires topical anesthesia, however, as the depth of the laser and the heat delivered can be very painful.

    The 1,320 nm laser has also been used in acne. After three treatments in a split-face controlled trial, Orringer et al demonstrated a 27 percent reduction in open comedones when using a 1,320 nm Nd:YAG laser.



    Another light option with little to no downtime is the IPL (400 nm to 1,200 nm) with pneumatic device. This suction device brings the target closer to the light source while stretching and obscuring competing chromophores. The suction device extracts open comedones during the procedure as well (Gold MH, Biron B. J Drugs Dermatol. 2008;7(7)639-642).



    IPL devices may have an additional role in the treatment of rosacea. Demodex mites can be coagulated via absorption of light (500 nm to 1,064 nm) by their pigmented exoskeleton (Goldberg, Dover. Laser and Lights, Elsevier).



    Insurance's impact



    Despite the lack of support from U.S. insurance companies in covering these procedures, there are some well-designed published trials supporting the use of optical treatments for acne. The lack of insurance reimbursement has a huge influence on the amount of procedures performed, as the out-of-pocket expense can be too high for many patients.



    Economics aside, for those patients looking for a nonsystemic, convenient alternative, laser and light devices do provide results. Proper counseling of realistic expectations is mandatory with these therapies, as lesion-reduction rates are inconsistent (ranging anywhere from 0 to 83 percent). These results depend on the type of device as well as the type of acne.



    The future of acne treatment will definitely include light devices, and better delineation of treatment protocols will help streamline these therapies into consistent players in the acne market.

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    Source : Laser, light devices useful in clearing obstinate acne lesions - - ModernMedicine
     

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