Melasma is light brown pigmentation of the skin which is harmless. They are gradually blotchy macular hyperpigmentation especially of the malar surfaces, chin or forehead. Origin can be pregnancy related to the use of Oral Contraceptives. A good number of cases are idiopathic. They are self limiting after pregnancy and when OCP is discontinued. Ref: In a Page: Signs and Symptoms By Scott Kahan, 2004, Pages 81-82