People with melasma get dark patches on the parts of their skin exposed to the sun. After the patches appear, they do not go away. They can get darker and larger.
The cause is not fully known. Causes can be genetics, hormones, and sunlight. It is most common in premenopausal Latino, African American, Asian, and Native American women. Many people have a family history.
You will have:
Even small doses of sunlight can make patches worse. Read about sunscreen for more facts.