DERMATOLOGIST TIPS ON SUN PROTECTION

What type of sunscreen should you choose and how do you apply it?

How much sunscreen should you be applying and how often should you re-apply?

Most people do not apply enough sunscreen to achieve the specified SPF rating. SPF stands for “Sun Protection Factor” and to achieve full protection, you will need 2 mg of sunscreen applied for each cm2 of skin, which is the basis of an SPF rating achieved in the laboratory setting. A good gauge could be a quarter to half teaspoon to cover the face, or approximately 1.2 ml of sunscreen (taking an average face size skin surface area of 600 cm2).

For daily use, reapplication is advised every 2-3 hours. Reapplying sunscreen or double application helps to ensure coverage of areas that you may have missed the first time.

For outdoor sports or activities, ensure that sunscreen is applied before leaving the house instead of putting it on only on the beach for example. Studies have shown that 15 to 59 per cent of the sun protective effect of a sunscreen can be lost after contact with sand; while 20 to 40 per cent is lost with immersions in water. The 2-hour reapplication rule applies, and it is especially recommended for individuals to adhere strictly to it when engaging in outdoor activities.

Is there a sunscreen type that is better suited for certain types of activities compared to others?

Sunscreen sticks can be practical for application to areas close to the eyes. With a thicker consistency, the sunscreen is less likely to run into the eyes. Yet, sunscreen sticks may generally be harder to apply to large areas of the body, which can lead to a less than adequate amount of sunscreen applied – with some studies indicating a mean application rate of just 0.35 mg/cm2 with sunscreen sticks.

Parents of young children may prefer sprays as they are easy to apply on children. Sunscreen sprays can reach the intended 2 mg/cm2 concentration much easier than other forms of sunscreen, after factoring in the potential amount lost to surroundings during the spray application. On the downside, the often lack of application safety guidelines regarding spray sunscreens is a concern. While sunscreen chemicals are safe for topical application, there is a lack of safety data in respect of inhaling it. Make sure your child or yourself is not inhaling the sunscreen as you spray, otherwise, switch to a traditional sunscreen lotion.

The most efficacious and all rounded form of sunscreen is perhaps still the traditional topicals in the form of lotions/creams that is used regularly and in adequate amounts.

Are there any specific application techniques that should be used for the newer types of sunscreens?
• Sunscreen Stick
• Sunscreen Mist
• Cushion Compact

For use of traditional sunscreen lotion/cream, rubbing should be avoided as it can decrease the SPF up to 20 per cent. Stick to gentle application, such as patting it into the skin. When using a spray sunscreen, rubbing in the sunscreen immediately after spraying is necessary for even distribution and proper coverage, whilst great care should be taken to avoid inhalation of the sunscreen during application. Sunscreen sticks may require more frequent reapplications given the lower amount applied on the average as discussed above. 

With these new sunscreen types, how would you know if application has been done properly so that skin is well-protected? Are there any extra things one should take note of?

It is hard to tell if the sunscreen applied is well covered, and some specific areas of the face that are commonly missed could be around the eyes and periorbital regions. UV-blocking sunglasses can be an alternative mechanism of sun protection for those areas.

There is limited data on the efficacy and safety on some of these newer types of sunscreen, so I would generally recommend my patients to keep to the conventional topical lotion/cream form, which is the most well established at present. Whichever brands or types of sunscreen you use, do remember to reapply and in adequate amounts to achieve the desired sun protection.

With so many different types of sunscreens to choose from, in your opinion, would it be beneficial for us to have one of each type for a better holistic (360) sun protection care?

Choose a sunscreen that provides protection against UVA and UVB rays – “broad-spectrum”. There is no need to have one of each type of sunscreen if you apply the recommended amount of 2mg/cm2. If sunscreens were applied properly as they were designed to, there would perhaps be no need for SPF ratings greater than 15. SPF is derived by taking the time it takes you to burn with sunscreen on and dividing it by the time taken for you to burn without sunscreen on. Imagine that your skin normally begins to burn after 10 minutes in full sun without any protection, an SPF 30 sunscreen would provide 30 times the protection of no sunscreen. If you use SPF 50, due to applying too little or not reapplying every 2 hours when outdoors, the overall protection will be about an SPF 20. I would recommend a minimum of SPF 30 for an everyday sunscreen and SPF 50 when outdoors for extended periods of time. The labelling of super-high SPFs (70 and above) are controversial, as they may not offer added protection beyond SPF50.

For a broad-spectrum sunscreen with SPF 50, I have formulated for my practice the SunProtector™, a sunscreen which employs both chemical (e.g. salicylates) and physical (e.g. titanium dioxide) mechanisms for broad spectrum sun protection, whilst infused with skin smoothening agents such as glycerine and sodium hyaluronate for a lightweight, invisible yet moisturizing lotion that is especially comfortable for the humid climate in Singapore. Harnessing also the power of potent plant antioxidants and oligopeptides, the sunscreen helps in soothing skin sensitivity and supports skin repair, catered for my patients undergoing dermatologist treatment for skin conditions, which can be acne, rosacea, eczema or photosensitive skin conditions such as seborrheic dermatitis, cutaneous lupus, actinic dermatitis and other medical conditions. It is also suited for skin that is sensitive or skin that has undergone laser treatments/chemical peels.

Any other sunscreen tips you would like to offer?

As a dermatologist, I am passionate about raising general awareness of skin conditions and I find that the importance of adequate protection against UV rays from the sun is one area which the average person frequently overlooks. For example, one may be unaware that all scars including acne scars turn darker with increased sun exposure due to ultraviolet radiation which triggers the production of melanin that leads to darkened pigmentation in existing scars. Also, UVA is predominantly involved in skin ageing and pigment darkening whereas UVB also has additional dangerous effects of increasing the risks of skin cancer. Apart from sunscreen, other forms of photoprotection exist. From most to least effective, methods include: sun avoidance, seeking shade, the use of protective clothing/gear, and the application of sunscreen. Sunscreen should therefore be used alongside with other protection strategies to avoid excessive exposure to harmful UV rays.

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