the science of dark spots
But what causes dark spots? Sometimes – in response to a variety of internal or external triggers – the skin produces irregular amounts of melanin, which leads to color-clumping at the skin’s surface. This over-production is the root cause of dark spots. This next section investigates the triggers that lead to hyperpigmentation, the anatomy of a dark spot, and how best to treat them.
what causes dark spots?
Though melanin naturally protects our cells, the skin occasionally overproduces melanin. This overproduction of melanin is what causes dark spots, also known as hyperpigmentation. Here are some of the top dark spot triggers:
Unprotected sun exposure is the best-known trigger for melanin production (think about the tan you get from a day at the beach). It’s also the leading cause of dark spots; much of the hyperpigmentation we treat is the result of sun exposure. Fortunately, UV-induced hyperpigmentation is widely considered to be the easiest type to treat.
Airborne particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) can both become lodged in skin’s deeper structure. This oxidizes the surrounding tissue – leading to free radical damage and triggering an inflammatory response that results in hyperpigmentation.
Collectively known as Reactive Oxygen Species (ROS), free radicals are oxygen-derived molecules with unpaired electrons, which makes them highly reactive and able to damage macromolecules such as lipids, proteins and nucleic acids. The free radicals produced by keratinocytes can overstimulate melanocytes, resulting in hyperpigmentation.
During pregnancy, we often see melasma, also known as chloasma or “the mask of pregnancy,” on the face. This can be either temporary or permanent, and is caused by hormone shifts during pregnancy. Even medications such as birth control can induce hormonal dark spots.
Any trauma to the skin, whether it’s a wound, breakout, or even a medical procedure such as resurfacing or laser hair removal, can cause melanocytes to be damaged over overstimulated, resulting in post-inflammatory hyperpigmentation (PIH). Darker skin types are particularly suseptible to this type of hyperpigmentation.