Melasma is a skin condition that can occur as a result of hormonal imbalances. Melasma is also known as cholasma and, while there is a definite genetic component to the disease, it is generally triggered by hormonal changes. The most common reasons for these hormonal imbalances to occur is pregnancy or the beginning of using hormonal birth control. Melasma occurs when the melanocytes (which are cells that cause skin pigmentation) are stimulated by abnormal levels of progesterone and estrogen. This causes these cells to produce extra levels of melanin (the compound responsible for skin pigmentation), resulting in skin discoloration.
The primary symptom of melasma is skin discoloration. Melasma can affect either the epidermis (top layer of skin) or the dermis (second layer of skin) or both, yielding different symptoms. Melasma of the epidermis tends to cause spots with a dark brown color and a well-defined border. Melasma of the dermis tends to cause lighter spots that are not as well defined. If the melasma is affecting both layers of the skin, it will cause a mixture of light and dark spots. Melasma of the epidermis tends to be easier to treat than melasma of the dermis, partly because the cells of the epidermis tend to be replenished more often.
Melasma can take a long time to treat. The most effective method of treatment is to correct the underlying hormonal imbalance (either having the pregnancy end in birth or by stopping the hormonal birth control). Other treatments involve using sun protection (such as sunscreen) all throughout the year, usage of bleaching creams, or using mild solutions of cleanser. This treatments may irritate the skin and cause post-inflammatory pigmentation. Other, stronger treatments include corticosteroid creams and salicylic acid to treat to peel off the pigments. These methods may not be completely successful and commonly need several months to be effective.