Freckles are small pigmented spots that often appear on the surface of the skin, usually light brown or dark brown. They can range from the size of a pinhead to a green bean. The shape is usually round or oval, but there are also irregular shapes, with clear borders and a diameter of about 1~2 mm. Freckles are easily found on the face, especially on the nose and cheeks, and can involve the exposed parts such as neck, shoulders and back of hands, but there is no rash on non-exposed parts. Freckles are autosomal inherited diseases, often accompanied by family history, easily appearing at the age of 3~5 years old, often aggravated around puberty, without any conscious symptoms. The number, size and color of the pigment spots depend on the amount of sunlight absorbed and the tolerance of the individual to sunlight. Therefore, the number and size of freckles are large and dark brown in summer, but they are reduced in winter. Usually, freckles affect the beauty of the face, bring psychological pressure to the patient and affect social confidence. Here are several common treatment methods, which have their own advantages and disadvantages: 1. Decolorization treatment: 3%~5% hydroquinone cream, 0.1% vincristine ointment, 3%~5% arbutin cream, 20% azelaic acid cream, etc., which can have certain effect if used externally for several months. The disadvantage is that the treatment time is long, and the efficacy is poor. 2.Corrosive and destructive treatment: In the past, liquid nitrogen freezing, trichloroacetic acid or phenol dabbing, mechanical grinding, electrocautery and general carbon dioxide laser were used to treat freckles, all of which can make freckles peel off. The disadvantage is that the above treatments are not selective to skin lesions, and the treatment is too deep to cause depressed scar or hyperplastic scar, and may lead to pigmentation or leave sequelae after decreasing. At the same time, the treatment process is too painful and difficult for patients to accept. 3.Laser selective treatment: Modern Q-modulated laser and pulsed dye laser are highly selective in the treatment of freckles, which have no damage to the surrounding normal skin, no scar, no pigmentation and other adverse reactions, so it is the best treatment for freckles at present. In terms of prevention, one should try to avoid or reduce the exposure to the hot sun, or apply sunscreen-like light-avoidance agents to reduce the occurrence of freckles or the deepening of freckle color.