Write an article based on this "Identify the different types. Understand post-inflammatory hyperpig­mentation (PIH). Identify lentigines. Determine melasma hyperpigmentation."

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Hyperpigmentation can take a variety of forms and have a number of different potential causes. If you want to try and prevent it, it's important to have a clear understanding of the different ways it might appear to see for which form you are most at risk. Depending on what form of hyperpigmentation you are concerned about, you may not be able to do much to prevent it. The three main types are:  Post-inflammatory hyperpigmentation Lentigines Melasma This type of hyperpigmentation can be caused by any inflammatory skin condition which involves the junction between epidermis and dermis. The epidermis is the outermost layer of skin and the dermis is the layer beneath that. The kind of inflammation or injury that can cause PIH includes acne, burns, and psoriasis. A professional skin treatment can also result in PIH.  If PIH is a reaction to a specific inflammation or trauma it can resolve itself without treatment, but this can sometimes take months. It is possible that epidermal pigmentation can last for six months or a year. Dermal pigmentation can last for even longer, persisting for years. There are a wide variety of different instances of lentigines recorded in medicine. Some of these develop when you are very young and some as you get older. Solar lentigines are those which are most often caused by excessive exposure to the sun. Sometimes these are known as liver spots, and have been associated with aging. Although they do multiply and become more prominent with age, evidence has shown them to be much more prominent in older people who have had high exposure to UV light.  Solar lentigines most frequently occur on the face and the back of the hands. There is no proven link between lentigines and melanoma (a serious form of skin cancer), but they are considered an independent risk factor for melanoma. One other common type of hyperpigmentation is known as melasma (sometimes referred to as chloasma). Unlike the PIH and lentigines, melasma is not caused by exposure to the sun or a trauma or inflammation experienced by the skin. Melasma is understood to result from hormonal fluctuations, most commonly during pregnancy.  Melasma takes the appearance of dark brown, roughly symmetrical patches on the face, which have clear distinct edges. Melasma can be a side-effect of oral contraceptives for women. It is often aggravated by thyroid complaints. It is more prevalent and tends to persist for longer in people with darker skin, and is sometimes experienced by dark-skinned men. For women, melasma often fades slowly after pregnancy, when hormonal fluctuations desist; however, it may never completely disappear without treatment.