Brown-cyanotic nevus, also known as zygomatic mother spot, is a congenital non-genetic skin pigmentation disease. 1.Brown nevus overview Brown nevus (dermal spot) is a kind of congenital non-genetic skin pigmentation disease, because it occurs in zygomatic bone and is also called zygomatic mother spot, and the pigment is deposited in the dermis, which makes it have the name of dermal spot. Zygomatic nevus (dermal spots) mostly occurs in women, and the age of onset is mostly from 16 to 40 years old, and some patients have family history. The main pathological characteristics are dark gray spots with a diameter of about 1-5 mm distributed symmetrically on the cheek, without any conscious symptoms. Some patients with melanosis (dermal spots) have a family history. The disease needs to be distinguished from nevus of Ota and freckles. Most of the nevus of Ota has unilateral distribution and travels along the ophthalmic and superior frontal branches of the trigeminal nerve, with early onset, mostly at birth or at the age of 1 to 2. The lesions of freckles are yellow-brown spots, relatively small, with early onset, mostly within 5 years of age, with obvious seasonality and aggravation in summer. 2.Brown nevus treatment The earlier the cheek brown nevus (dermal spot) is treated, the better the effect. Because the younger the age, the better its absorption and the less pigment particles are deposited, the better the treatment effect. In addition, the area is small in the early stage, but becomes larger and the pigment color deepens in adults, which makes the treatment more difficult and increases the treatment cost. The Q-switched laser can achieve very satisfactory results in the treatment of zygomatic nevus, which is based on the principle of selective photothermal absorption, targeting the deposited pigment particles in the dermis and breaking them up with its powerful instantaneous power, highly concentrated laser energy and high pigment selectivity, and discharging them out of the body through lymphatic tissues without affecting the surrounding normal tissues, thus achieving precise efficacy, no damage, no scar, less pain and less treatment cost. This results in precise, non-invasive, non-scarring, less painful and safe treatment. Because the pigment is burst in the dermis, it is unlikely to be burst at once or metabolized immediately. Therefore, Q-switched laser treatment for brown nevus generally requires about three treatments, with an interval of three months between each treatment, to allow the body’s phagocytes to completely metabolize and absorb the smashed pigment particles and then discharge them from the body. 3.Note: After laser treatment, different degrees of skin edema and skin bleeding will occur at the treatment site (the degree varies according to individual differences), and ice can be applied to reduce edema and burning sensation. The recovery period is characterized by the disappearance of edema, crusting in three days, and scab removal in one week. During this period, antibiotic ointment is applied once or twice a day to prevent local skin infections, and do not participate in strenuous sports during the healing period to avoid prolonging the recovery period due to excessive sweating. It is best to let the scabs fall off automatically when they are removed. During this period of time, the treated area should not be exposed to water, makeup, rubbing, alcohol, aspirin, or face masks, and should be protected from light otherwise transient hyperpigmentation will occur.