Melasma is a disorder of pigmentation caused by excessive production. of Melanin by melanocytes. Melasma is a skin condition that causes patches and spots on the face, which are darker than your natural skin tone. Most people get it on their cheeks, chin, nose bridge, forehead, and above the upper lip. It sometimes affects your arms, neck and back also. In fact, melasma can affect any part of your skin that is exposed to sunlight. That’s why most people with melasma notice that their symptoms worsen during the summer months