Detailed answer

Melasma is a common skin condition characterized by darker patches of pigmentation on the face. It is usually caused by hormonal changes, sun exposure, or genetic factors. Melasma often occurs during pregnancy or with the use of hormonal contraception. Lentigines, on the other hand, are small dark spots or patches on the skin caused by excessive melanocyte activity. They are commonly known as age spots or liver spots and are usually a result of cumulative sun damage. Unlike melasma, lentigines are not influenced by hormonal changes. Both conditions can be treated with topical treatments such as hydroquinone or retinoids, as well as procedures like chemical peels or laser therapy.