Ask an expert: Living on the rainy west coast, do I really need to wear sunscreen on cloudy days?

Dr. Tim Lee explains why sunscreen is needed even on a grey, cloudy day and why it’s important to pay attention to any changes in your skin.

Q: Do I need to wear sunscreen even if it’s cloudy and overcast outside?
Yes, you should wear sunscreen even if it’s cloudy and overcast outside because we do not know exactly which wavelength of UV light causes skin cancer and there are possibly still wavelengths making it past those grey clouds and being absorbed by your skin. Researchers suspect that it’s the ultraviolet light B (UVB) wavelength that causes skin cancer, but we can’t say for sure. And so, because of this uncertainty, most dermatologists and dermatology societies caution people to act on the safe side and wear sunscreen even on cloudy days. 

Q: What are sunspots? Should I be worried about the growing number of sunspots I’m getting as I age? 
Sunspots are flat, brown spots that usually develop as we age and appear on parts of the skin that are exposed to sunlight, such as the face, arms, shoulders and hands. While they are very common and harmless, they are indicators of sun exposure and we should view them as a reminder to be more careful about being in the sun too much.

Q: Are freckles the same thing as sunspots?
Freckles are an inherited skin feature most often found in people with fair skin tones. Like sunspots, freckles also appear as flat, brown spots. However, freckles typically become more prominent in the summer months when you are spending more time outside in the sun and they usually fade or disappear altogether in the winter. 

Q: How do I know whether a mole is just a mole or if it’s something that I should have looked at by a doctor?
A mole is usually a small, round growth on the skin with a single colour. If you have a mole and you notice that it is changing in size, shape or colour, or it becomes irritated or itchy, that is a cause for concern and you should check in with your doctor immediately. 

Q: What is melanoma and what are its symptoms?
Melanoma is the most dangerous form of skin cancer. Its symptoms are often described using the ABCDE rule when it comes to lesions, such as a mole, on the skin. A = Asymmetry (one side of a lesion looks different from another side), B = Border (a lesion has irregular or scalloped edges), C = Colour (a lesion is marked with multiple colours), D = Diameter (the size of a lesion is greater than 6 mm), E = Evolving (a lesion changes in appearance or becomes irritated or itchy).

Q: Why is it important to discover melanoma early? What are some helpful resources to learn more about melanoma?
Melanoma is a deadly disease, but it is curable if diagnosed and treated early so it’s vital to visit your doctor if you think you have symptoms. To learn more about melanoma, including information on diagnosis and treatment, visit BC Cancer and the Canadian Cancer Society websites.

Dr. Tim Lee is an associate professor in the Department of Dermatology and Skin Science within the Faculty of Medicine at the University of British Columbia. His research interests focus on developing early detection tools for melanoma and understanding risk factors of the disease. 


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