Reader's Question: I have a few brown spots on my face. Are these cancer? If they're not cancer, what can I do to get rid of them?
Sue's Response: Unfortunately for all of us, melanocytes just can't stop working overtime. As I've discussed in previous posts, melanin (released by melanocytes) is a key component of our bodies' defense against sun exposure. This is why darker people burn less easily after sun exposure and why lighter people are most often affected by skin cancer. However, a newly darkened area on your skin doesn't always turn out to be melanoma.
These dark patches on the skin are called solar lentigenes, hyperpigmentation, or less formally, sun spots. These discolorations are not cancerous and don't cause negative effects on your skin health. If you neglect sunscreen or have neglected sunscreen in the past, chances are you have a few of these sun spots on your face, neck and hands. People with darker skin tones may experience these solar lentigenes as patches of ashy or gray skin.
Your mother may have referred to them as "liver spots," but these darker areas have no connection with liver function. Instead, they are mostly the result of sun damage, much like a freckle that appears after a summer in the sun. Occasionally, these darker patches appear on the face and neck as a result of hormonal changes (most often due to pregnancy) and also appear after cuts and blemishes heal on darker skin.
Melanocytes release melanin when it gets triggered by an enzyme known as tyrosinase. Melanin-inhibiting ingredients most often attempt to stop this enzyme before it spurs an increase in melanin production. There are a few topical methods of fading the spots, but the most effective way involves a combination of sunscreen, tretinoin and hydroquinone.
You've heard this before, but it bears repeating: Using sunscreen every day and avoiding any unnecessary sun exposure will not only prevent further damage but also allow your skin to repair itself to an extent. Use a broad-spectrum sunscreen that blocks both UVA and UVB rays by looking for both physical (titanium dioxide or zinc oxide) and chemical (avobenzone) sunscreens. Without sunscreen, other methods of fading these spots will have little benefit since those treatments will not cancel out your continuing exposure to the sun.
Kojic acid, a by-product of the fermentation process of Japanese sake, shows some improvement in fading the skin because it inhibits tyrosinase. However, the ingredient is known for its instability in cosmetic formulas. Tretinoin (known by its brand name as Renova) also shows some improvement in fading sun spots. Azelaic acid, derived from grains such as wheat and rye, also shows promise in terms of fading hyperpigmentation.
Hydroquinone, which has been used in cosmetics for over 30 years, remains the best bet. Most topical formulas contain two to four percent concentrations and, combined with the use of tretinoin, show significant success in inhibiting melanin and fading sun spots.