Understanding your skin's pigmentation
Several years ago I was visiting a family member in the US in Seattle Washington. I was living in Perth at the time, where blotchy skin known as hyperpigmentation and freckles was a very common phenomenon and almost unavoidable, especially with individuals of a certain age.
It was autumn in Seattle. The maple trees where changing colour to vibrant red and golden tones and the landscape was welcoming for outdoor activites. However, Seattle is renowned for its cold, long, and rainy winters with very little sun exposure. As a skin therapist, what amazed me most when observing the locals was how clear and blemish-free their skin looked compared to Australians.
Everyone loves a smooth and flawless skin, but living in a wonderfully sunny country like Australian has its pitfalls. One of these is the constant battle we all – but particularly women – have with a condition called hyperpigmentation.
Hyperpigmentation can be characterised by the presence of uneven skin tone, brown spots and discolouration of the skin. We usually experience this in our late teen years and onwards, and as we grow older, hyperpigmenation can become more obvious and severe.
How does it occur?
Skin colour begins down in the deepest level of your epidermis, where special cells called melanocytes live. These melanocytes are big round blobby cells, with lots of arms that reach up into the upper levels of the skin cells. Melanocytes make a dark chemical called melanin.
So you may ask, “If I have fair skin, does that mean that I have less melanocytes?” Strangely enough, this is not true. In fact, whether you are very fair with light skin you still have roughly the same melanocytes as, say, a black African. What gives colour to different skin tones is not how much melanin we have, but what happens to the melanin.
Inside the melanocytes, there is a chemical called Tyrosine, which is turned into a chemical called DOPA, which then gets turned into melanin, (you need to remember Tyrosine, as this is very important when looking at treatments for pigmentation.) The melanin is then packaged into little round blobs called melanosomes. They migrate up the arms of the melanocyte, heading towards the surface, and along the way, they (and the arm of the melanocyte) get eaten by your regular skin cells.
It's when the little package of melanin gets swallowed that you get the different skin colour. In the skin of a dark-skinned person, the complete melanosome, with its load of melanin, survives inside the regular skin cells - and this gives you a darkish skin. But in lighter-skinned Caucasians, the chemicals inside their regular skin cells break these melanosomes down, and even break down the melanin. Not much melanin is left, so they have a lighter skin.
But of course, like everything else in the human body, it's more complicated than that. There are two different types of melanin - the pheomelanin, which is a pale-reddish yellow colour, and the eumelanin which is a darker, brownish-black colour. This explains why you can have two different types of tan.
What happens when you tan?
When you first get hit by sunlight, the pale melanin gets quickly turned into the darker melanin, within an hour or so. So you get an instant tan, but it fades after a day or so. If you get exposed to even more sunlight, this stimulates the biochemical pathway to make more melanin, and even lengthens the melanin into longer chains. This gives you a lasting tan, which is deeper in colour, but it takes a bit longer to build up.
But the ultraviolet light from the sun can do more than just tan you when it hits your skin. It can damage your DNA. Down at the level of the molecules, it joins together the rungs in your DNA-Ladder-Of-Life. This stops the DNA from replicating and making more copies of itself.
And if that was not enough, the UV light also damages the proteins in the elastic and connective tissue layers of your skin. Eventually, you end up with a leathery, sagging and very wrinkled skin. In fact, it's chillingly accurate to use the word tan, which is normally applied to working leather, when describing these changes in your skin.
What causes hyperpigmenation?
Sun damage, inflammation, or other skin injuries may cause hyperpigmentation, including those related to acne vulgaris. People with darker Asian, East Indian, Mediterranean or African skin tones are also more prone to hyperpigmentation, especially if they have excess sun exposure. Hyperpigmentation is also associated with a number of diseases, but the most common causes of pigmentation is due to frequent sun exposure and sun damage and this is why we must take adequate precautions with regular and thorough use of sunscreen.
Hyperpigmentation can also become prevalent during pregnancy or for women who are taking birth control pills that cause changes in hormonal activity. These changes trigger uneven skin tone and blotchy skin.
When considering treatments that will help fade hyperpigmenation, there are several considerations. However, fading skin discolouration is a lengthy and slow process so prevention is always the best. A good beauty clinic specialising in skin management should be able to offer you both products and a series of treatments that will work in two ways:
- Utilising skin bleaching ingredients to fade pigmentation
- By inhibiting Tyrosine activity in the melanocyte through certain active ingredients.
The most common ingredients to treat hyperpigmentation may include hydroquinone, kojic acid, azelaic acid, ascorbic acid, tretinoin (Retinol), topical glucocorticoids, liquorice extract and white mulberry. However, it is important to remember that all such treatments will fail if the affected area is exposed to the sun with inadequate UVA/UVB protection.
Tina Viney is an industry consultant for the professional beauty industry.