What is melanin?
The basal layer is the innermost layer of the epidermis. Melanocytes produce skin coloring or pigment known as melanin. Melanocytes are in the basal layer, and they give skin its tan or brown color. Melanin also helps protect the deeper layers of the skin from the harmful effects of the sun. People of all different skin colors can get PIH, but it is more prevalent in fitzpatrick skin phototypes 3 – 6 (deeper skin tones) because they have more melanocytes.
What is post-Inflammatory hyperpigmentation (dark spots)?
There are different types of hyperpigmentation, but here, we’re focusing in on post-inflammatory hyperpigmentation or dark spots. An injury, rash, or blemish causes the skin to become inflamed, and inflammation triggers melanocytes to release excessive melanosomes or pigment granules. If there’s more inflammation, there’s more discoloration in terms of size and color. That’s why PIH often accompanies acne. The excessive pigment granules darken and discolor the formerly wounded area, and many times, they’ll remain long after the initial wound has recovered. This is known as PIH.
So, does glycolic acid help with PIH on skin of color or make it worse?
While many say that people with deeply colored skin should steer clear of glycolic acid, this claim is actually very generalizing. Because glycolic acid helps push new cells to the surface, glycolic acid can definitely help with PIH on melanin-rich skin as well.
An increase in PIH on melanin-rich skin due to glycolic acid is not widespread. Having more melanocytes does not equate to higher skin sensitivity. While a greater release of melanocytes is triggered by irritation, exfoliation is not synonymous with irritation although the two can happen at the same time. For example, over-exfoliation can cause irritation, especially on sensitive skin types. Therefore, PIH could be triggered by any sort of irritating ingredient to that person. It’s not specific to glycolic acid. Also, if you try to physically exfoliate or scrub after using an AHA, that might be what’s causing PIH rather than the actual acid itself. Moreover, everyone’s skin is different so chat with your derm or esthetician about the frequency and the extent to which you should an AHA.
If you’re unable to chat with a professional, perhaps avoid using one every day. Also, please remember to wear sunscreen after using an AHA because not doing so can also lead to sun damage. AHAs can make your skin more vulnerable to sun damage, and in turn, lead to PIH.
So, in short, AHAs might not be for everyone, but whether an AHA is right should be based on the individual, not their ethnic group.