According to the American Academy of Dermatology, melasma, a common skin condition affecting approximately 6 million women in the United States, causes brown or gray-brown patches of skin on the face. Patches can occur on the upper lip, chin, forehead, nose and cheeks. The upper lip may also look darker in color due to a shadow caused by hair growth.
Caused by hormonal changes and sun exposure, melasma affects women during their reproductive years, which are roughly between the ages of 20 and 50. While it's uncommon for the condition to affect men, it's not unheard of, says MedicineNet.com. Those who are genetically predisposed to the condition as well as pregnant women and women with olive skin tones are more susceptible. The ethnic groups most affected include Hispanic, Asian and Middle Eastern populations.
According to Skin Inc, there are several treatments for melasma, including hydroquinone creams, corticosteroids, chemical peels, microdermabrasion, laser therapy and the use of sunscreen to prevent further discoloration, as it becomes more noticeable after sun exposure. In some cases, a combination of treatments is used to lighten the skin and prevent more dark spots. The American Academy of Dermatology recommends applying sunscreen daily to the affected areas.