Melasma has a higher incidence than other pigmentation. How to know if it is melasma? To determine whether it is melasma or not, you can judge from its characteristics. Let’s take a look at the characteristics and causes of melasma. Melasma has three main characteristics: 1. Most of them grow near the cheekbones, forehead and mouth of the face, and present a butterfly symmetry; 2. inflammation phenomenon, and patients will not feel pain or itching. There are conditions for the aggravation of melasma: the shades of the spots will be affected by season, sunlight, endocrine and other factors; long-term mental stress, staying up late and overwork will aggravate the skin lesions. Causes of chloasma 1. Part of it is caused by high level of estrogen in blood, such as pregnancy, frequent use of birth control pills and irregular menstrual cycle; 2. Some women have chloasma because of reproductive system diseases, tuberculosis, cancer, chronic ethanol poisoning, liver disease, etc.; 3. The above teaches you how to determine the method of melasma. It also introduces you the etiology of this kind of pigmentation. The treatment method of melasma is to decide, according to the etiology, what method to use and what medicine to use. Generally, the treatment is internal combined with external treatment together.