Psoriasis is commonly known as “psoriasis”, and we often see small advertisements for “psoriasis treatment” on telephone poles and billboards. The answer is of course NO! The answer is of course NO! To treat psoriasis, you have to go to a regular hospital! I heard people say that light therapy can cure psoriasis? What is light therapy? It sounds amazing that a light can cure the disease! So let’s talk about light therapy for psoriasis! There are many treatment methods for psoriasis, and they are all different according to the characteristics, type and severity of the disease. For example, mild psoriasis is mainly treated with topical medication, topical glucocorticoids, carbotriol ointment or non-hormonal tacrolimus ointment; moderate to severe psoriasis requires the choice of systemic treatment (internal and external medication) and physical therapy (phototherapy). For severe patients with lesions larger than 10% (10 palms), phototherapy is a very important treatment. Why can phototherapy treat psoriasis? Psoriasis is a chronic inflammatory disease of the skin caused by an increase in the activity of T-cells in the body. When inflammation occurs, the skin thickens and becomes scaly. Phototherapy can inhibit the proliferation of T cells in the skin, inhibit the thickening of the epidermis, and reduce inflammation, thereby reducing skin damage (referred to as lesions). The most commonly used phototherapy is narrow-spectrum medium-wave UVB (narrow-spectrum UVB) and PUVA (combined UVB and photosensitizer therapy), of which narrow-spectrum UVB is simple, rapid and more commonly used, and PUVA must be applied after the application of photosensitizer (psoralen) before light exposure, and the duration of exposure is longer, so it is rarely used. Not all psoriasis are suitable for phototherapy As mentioned earlier, the treatment methods are different for different types and severity of psoriasis. Therefore, phototherapy is not suitable for all patients with psoriasis. The fewer the scales and the thinner the skin, the better the effect of phototherapy. The most suitable psoriasis for phototherapy are the following categories. The first category is spotted psoriasis, which is suitable whether it is a first episode, a generalized attack, or a large area of spotted psoriasis; the second category is plaque psoriasis, which can be used for a long time even if the patient has a large area of lesions (greater than 10% or even greater than 20% or 30%). Some psoriasis are less suitable for phototherapy, such as progressive erythrodermic and pustular psoriasis, which will be aggravated by phototherapy; arthritic psoriasis does not improve joint symptoms after phototherapy, so it is also not suitable for phototherapy. In general, an experienced doctor is needed to judge whether phototherapy is possible. Can pregnant women and children with psoriasis undergo phototherapy? Pregnant women and children with psoriasis are subject to many restrictions on the use of medication, so phototherapy is a good treatment option for them. Since the commonly used narrow-spectrum medium-wave ultraviolet radiation only irradiates the superficial layer of the skin and has no effect on the deeper layers of the skin and internal organs, it is as safe as sunbathing, so pregnant women and children can receive phototherapy as long as they can stand in the phototherapy chamber. The treatment requires protection of the eyes, external genitalia and other important areas. Many parents worry that phototherapy will not affect the growth and development of children, so I have to ask the question in return, does sun exposure affect the growth and development of children? Of course not! So parents can feel free to give their children phototherapy. Because children’s skin is relatively thin, doctors will slowly increase the dose of phototherapy.