All about sunscreen

What you need to know about sunscreen

Sunscreen is a topical cream which can be applied to reduce amount of solar ultraviolet radiation (UVR) that the skin absorbs. Although it is important to remember that sunscreen is not a substitute for sun avoidance or sun protection!

Sun avoidance should be practiced during the danger hours of 10am to 4pm as per WHO guidelines. If it is not possible to avoid sun exposure you should practice sun protection by wearing a hat, sun protective clothing with ultraviolet radiation protection, sunglasses with UV protection and finding shade under an umbrella or tree.

Types of sunscreen

      1. Physical sunscreen: Also called mineral sunscreen or sunblock. Options in this category include zinc oxide and titanium dioxide which are inorganic minerals. These minerals physically absorb and reflect the UV rays from the skin and therefore avoid absorption and resultant sunburn. This is a very good option and safe option for children as there is less chance of skin irritation. Physical sunscreens can leave a white residue on the skin which can be cosmetically unacceptable for some.
      1. Chemical sunscreen: Absorb UV rays before it can damage the skin and are soluble organic compounds. Chemical sunscreens usually do not leave a white residue on the skin.

 

What is SPF and how to choose the right sunscreen?

Sun protection factor (or SPF) gives you an indication of how long the sun’s UVB rays would take to redden your skin if you apply the sunscreen compared to not applying sunscreen. Therefore, if you use a SPF30 product as directed, it would take you 30 minutes longer to burn compared wearing no sunscreen.

If you spend most days indoors, you can use a sunscreen with a SPF of 15 or higher. If you spend a lot of time outdoors, you will need a SPF30 or higher with water-resistance. Make sure to choose a broad-spectrum sun screen with UVA and UVB filters to make sure that you get the best coverage to avoid sun damage.

How to apply sunscreen

    • Apply sunscreen daily 30 minutes before you leave the house in the mornings. Remember areas such as the tops of your ears, back of your neck, exposed scalp, tops of feet and behind the knees as these are easy to miss.
    • You should use about 1 shot glass of sunscreen to cover the whole body. Most people use small amounts of sunscreen which results in reduced efficacy and possibly results in sunburn.
    • To remain protected when outdoors, reapply sunscreen every two hours, or immediately after swimming or sweating.

 

Benefits of sunscreen

      1. Reduces your risk of skin cancer e.g. squamous cell carcinoma and melanoma
      2. Reduces your risk of precancerous lesions e.g. actinic keratosis
      3. Prevents photoaging due to sun damage
      4. Certain medications or skin conditions such as lupus or atopic dermatitis worsen with sun exposure and sunscreen can assist with reducing symptoms.

 

References:

    1. https://www.who.int/news-room/q-a-detail/radiation-sun-protection
    2. https://www.skincancer.org/skin-cancer-prevention/sun-protection/sunscreen/