A light bulb with a filter can produce this same wavelength of light, but you would have no idea what the output in joules per square centimeter (expressed as j/cm²) may be. So, LED refers to the Light Emitting Diodes producing the light. This is not a laser or intense pulsed light, but is light that you can rely on from the manufacturers’ specification for a particular machine, and that it is producing a set amount of j/cm² of a specific prescribed wavelength.
Photodynamic therapy refers to light used to specifically impact chromophores, or where the light waves perform specific functions. Light therapy is the consumer term for photodynamic therapy and sometimes even includes Laser and Intense Pulsed Light (IPL).
It is important to thoroughly comprehend these details, since you may be listening to what manufacturers’ representatives or fellow practitioners are saying. If these terms are not understood, you can be misled or possibly misunderstand the type of equipment being discussed and/or your licensing privilege to use such equipment. (A caveat emptor: when you decide that you want to invest in one of these pieces of equipment, obtain all of the specifics relating to your particular state’s licensing regulations and restrictions, so that when you are able to get the particular manufacturer’s specifics regarding the source of the light, the wavelength(s), and strength of the source, you will be able to make an informed decision.) We will use the term Photodynamic Therapy throughout the rest of this article to avoid confusion, and as it relates to the therapies for acne.
Acne is described by doctors as a disease of the pilosebaceous units of the skin. The mixture of oil and cells within the occluded pores allows the bacteria, Propionibacterium acnes (P. acnes), that normally live on the skin to grow in the plugged follicles. Acne patients have concerns relating to sebum control, in addition to issues regarding over- or under-exfoliation. In a medical setting, the aesthetician may be involved on many levels, at the direction or under the supervision of the physician, in the treatment of acne clients for their skin care needs.
The following are a sample of the options the aesthetician in a medical setting may use:
Microdermabrasion: Microdermabrasion may be used to gently exfoliate the client’s skin, and as a result, help to reduce the number of occluded pores that permit the opportunistic bacteria to develop into acne in that anaerobic environment. Depending on the study you read, this topical exfoliation helps clients with mild acne, and overall 20 to 30 percent of clients are satisfied with this addition to their skin care regimen, as long as their regimen is accompanied by the appropriate home care products.
Chemical Exfoliation: Exfoliating with the use of chemicals, in particular salicylic acid, helps acne clients with a client satisfaction of another 20 to 30 percent. Salicylic acid applications provide both antibacterial and anti-inflammatory benefits, while exfoliating the skin. Due to salicylic acid being lypophyllic, this type of treatment can actually penetrate the pore and oils to assist with exfoliation of the pore itself, thereby eliminating the anaerobic environment and killing the P. acnes bacteria.
Photodynamic Therapy: Yes, we have finally arrived at photodynamic therapy! Photodynamic therapy, when used for acne, has to do with the antibacterial aspect of the blue wavelengths of light. The blue range includes ultraviolet, while the specific range of ultraviolet wavelengths is often subdivided into UVA (400 to 315 nm); UVB (315 to 280 nm); and UVC (lower than 280 nm). Many reports have been published relating to UV exposure, and we know that this range of light may cause some potential for cellular damage. Even going out into the sun exposes the skin to the same UV wavelengths of damaging light, and as a result, most manufacturers have selected the particular wavelengths that purportedly cause the least amount of potential damage. No tanning beds should ever be recommended by aesthetic personnel for the photodynamic advantage of those beds, due to the overall cellular damage they have been reported to cause. Therefore, this is the real advantage to photodynamic therapy for acne: it is safely dosed for the client and has a reported benefit to approximately 30 percent of acne clients in peer-reviewed journals. This antibacterial advantage is transient, as the opportunistic bacterial still will take advantage of occluded pores, and the photodynamic therapy must be routinely repeated.
Photodynamic Therapy with Levulinic Acid: There has been evidence from a number of relevant studies that indicates an adequate exfoliation prior to the application of the photodynamic therapy using photo reactive agents such as the chemical D-Aminolevulinic Acid (trademarked Levulan®) allows a more complete penetration of the drug. With dermatologist treating severe acne, it is imperative to establish an exfoliating protocol to reduce the bioload. In particular, exposure to the 380 to 440 nm range causes a phototoxic reaction that attacks the bacteria that are part of the inflammatory causes of acne. In order for Levulan® to work on acne, it must access the sebaceous glands where, when it is exposed to the UV LED, it causes a similar outcome as the use of the oral prescription Accutane®. The photodynamic therapy with Levulan® results in a significant reduction in the oil production, or “food” that the acne bacteria feed on, but without the side effects of systemic antibiotics or Accutane®. Levulan® can also be activated by IPL, as a wavelength peak for activation also exists in the red range for Levulan®.
This procedure is always performed at the direction or under the supervision of a physician because the product is controlled and sold to physicians only, thus the procedure is done only in physician offices or medical spas. This process is repeated over several visits (usually four to seven) for photodynamic therapy with levulinic acid. After each application, the patient cannot be exposed to additional sunlight, as the activation of the levulinic acid will continue in sunlight exposure. Initially, levulinic acid was prescribed as a topical treatment that was to be followed by a specified amount of time in the sun. That was a big Oops! Some days are cloudy and some are not, but that does not mean you are not getting exposure. Overexposure results in significant burning and discomfort. Now that LEDs are available, and even with a fluorescent filtered light device, the amount of energy can be controlled. A controlled exposure to the particular blue wavelengths can be obtained by simply timing the treatment based upon the equipment being used.
Attention needs to be paid with regard to the percentage of clients or patients satisfied with their improvement for the services discussed above. These patients will achieve results through a combination of services and medical treatments that will afford them the opportunity to avoid the systemic use of Accutane®, which has come under close scrutiny due to its severe side effects.
The exciting opportunity with regard to all of the modern techniques and services described herein is that it involves the aesthetician in an active, integral, and intimate part of the treatment and care of acne in a medical office or medical spa. Aestheticians will recognize that they have an opportunity to take a very active role in the treatment of acne, in conjunction with the patient’s medical practitioner. This has been assured with the entry of photodynamic therapy into the treatment plan.