Causes of Dark Skin on the Chin
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Black spots, or hyperpigmentation, are a common dermatological complaint affecting both men and women. It is a condition in which the skin pigment melanin is unevenly distributed in the skin. These spots are medically harmless provided they do not thicken or change color, which may indicate skin cancer. Dark spots appear more frequently on the face and can make you feel self-conscious about your appearance. There are several conditions that can cause black spots to appear.
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Age
Dark spots are common in aging skin. As the skin ages, melanin, or skin pigment, production increases while the structure of the skin deteriorates. This causes loose, saggy skin and the appearance of dark spots.
Ultraviolet light
Dark spots normally appear on the skin when it is exposed to the sun for long periods without protection. Ultraviolet rays can cause freckles and melasma, which are large tan-colored spots that commonly appear on the face or any other sun-exposed locations. Applying sunblock lotion with a sun protection factor, or SPF, of 15 or above to the skin is recommended before going outside.
Medications
Certain drugs can cause dark spots. Hormonal pills during pregnancy can cause hormonal fluctuation and cause them. So can antibiotics, such as tetracyclines, and oral contraceptives, such as estrogens.