What is hereditary freckles?

Freckles, commonly known as "meng lian sha," are hereditary in nature and are associated with hormonal imbalances and weak metabolic functions of multiple internal organs. Under ultraviolet radiation, the activity of tyrosinase in the basal layer increases due to the freckle genetic predisposition, leading to melanin formation, which results in freckles—also known as genetic spots. Hereditary freckles can be categorized into two types: dominant and recessive. Dominant freckles typically begin to appear between the ages of 6 and 12 and peak around age 18. Recessive freckles usually appear on the face after pregnancy reactions. This distinction explains why some people classify freckles as either congenital or acquired. During pregnancy, significant hormonal changes occur, which can trigger the appearance of previously hidden recessive freckles. All freckles caused by genetic factors are considered hereditary freckles. Freckles may also exhibit the characteristic of skipping generations genetically, which is why some children develop freckles even when neither parent has them.