What is acne? Acne is commonly referred to as pimples. It mainly grows on the face, but can also grow on the forehead, back and buttocks. It is best seen in young men and women. In recent years, the incidence of acne in women around the age of 40 has increased significantly and is not uncommon in clinical work in dermatology. Acne is a skin disease characterized by Propionibacterium acnes infection accompanied by a series of other complex changes. Zhang Shide, Department of Dermatology, Fuding Hospital What is red and blue light? Why can red and blue light treat acne? Red and blue light treatment for acne is currently nothing new in China. Both red light and blue light are wavelength specific, as scientific research has found that specific wavelengths of blue light, with a wavelength of roughly 400+ nanometers, can kill the acne-causing Propionibacterium acnes, thus achieving the purpose of treating acne. Red light, in fact, is not a new light and was used clinically many years ago because it can reduce inflammation, astringent skin wounds and promote skin healing. Acne, in general, is accompanied by an inflammatory response, so red light helps the inflammation of acne to subside. Red light and blue light combined to treat acne can complement each other’s strengths and work in tandem to treat acne from multiple aspects, achieving the goal of rapid treatment of inflammatory acne. Which patients should be considered for red and blue light treatment? Because red and blue light is a physical treatment, the light acts directly on the lesion, unlike drugs, which are metabolized by the liver and kidneys after being taken orally. Because acne is treated like a cold and fever, it gets better quickly, and some patients have to take drugs for a long time if they are treated with drugs alone, so patients are worried! Can my body stand taking medication for a long time like this? Will it have an effect on my liver and kidneys? I already have small or large triple yang ah, I have kidney disease ah, what should I do? Doctor, can you not take medicine or take less medicine ah, I am afraid of taking medicine. It is for these objective reasons that red and blue light was created. During the treatment with red and blue light, patients can take less medication and treat acne better. There are also some patients who have acne and like to take Chinese medicine. In fact, Chinese medicine also has side effects, and some of them are quite large, and besides, when you take Chinese medicine, it is usually a few months. In view of this, then, which patients can consider combined red and blue light treatment? First, patients with other organ diseases, especially those with liver and kidney diseases; second, patients who want to take less medicine while treating acne. How are the cycles and courses of red and blue light treatment set? Red and blue light treatment for acne in dermatology is generally set up in this way: 2-3 times a week, 20-25 minutes each time, alternating between red and blue light, generally 6-8 times a course. As for how many treatments acne patients need, it varies from person to person. Some patients will have significant results within 2 treatments, while others will need 4-5 treatments.