Sunscreens are an essential thing to use if you spend a good amount of time outdoors. If your skin is sensitive to light or heat , you could even consider wearing a sunscreen indoor as well. However if you have a definitive skin condition it is always better to see a dermatologist first.
When you buy a sunscreen product, it is often influenced by the suggestions you get from your family and friends or some product advertisements. However, unlike many other things choosing a sunscreen is more of a medical decision rather than a cosmetic one because ideally your choice of sunscreen should be based on some complex factors. In the following sections we will try break it down into some easily understandable points.
Let’s start from the beginning. The sunlight we can see is only the visible part of it. But it has an invisible part which we call ultraviolet or UV rays. UV rays are usually responsible for all kinds of damaging effects that sunlight might have on our skin ranging from simple sun allergy to skin cancer. However, UV ray is not one single component rather it is like a spectrum and can be divided into 3 parts.
In simple math, the amount of sun protection is 100 x ( 1 - 1/SPF) % . For example, when SPF is 50, the amount of sun protection is 100 x (1 - 1/50) = 98%, whereas for SPF 15, the sun protection is 100 x (1 - 1/15) = 93%. So you can see the difference is not as big as it looks.
However, if you are staying outside for long, minimum SPF 30 is recommended. And if you have a skin condition that might turn worse because of sun exposure, SPF 50 or above is preferable.
Apart from UVA and UVB , there is also a UVC spectrum but we usually do not worry about it as it gets absorbed by the ozone layer of our upper atmosphere.
So your sunscreen should give you protection from both UVA and UVB part of the UV rays.
Key Takeaway : look for both SPF and PA ratings
If you have a definitive skin condition that gets aggravated by sun exposure (such as melasma), you might need protection from visible light and heat (infra-red spectrum) as well. There are certain specific physical sunscreens that can offer you that. However, it is best to let your dermatologist assess if you need that or not.
This difference is based on how your sunscreen actually works.
Also note that a single sunscreen product can have both physical and chemical sun blocking agents.
We usually prefer physical sunscreen due to some very specific reasons.
The only downside of using a physical sunscreen is that they are usually more costly. But if you look at the benefits, it's well worth it.
Key takeaway : Try to choose a sunscreen with physical sunblocking agents.
This one is pretty straightforward. Oil based sunscreens are not suitable if your skin is oily or you often get pimple breakout. Water based sunscreen is usually preferred even in the dry skin where you can easily combine it with a moisturizer if needed. Oil based sunscreens also causes more sweating causing skin irritation and also washes the sunscreen away.
Sometimes you will hear a term “matte finish” to describe a sunscreen product. It means that it will blend very well with your skin and no uneasy sticky sensation will be felt.
Key takeaway : Avoid oily sunscreen lotions specially if you have an oily skin
Certain few other things we suggest you take into account while choosing a sunscreen product.
Sunscreens should be used 15-20 minutes prior to expected sun or heat exposure (going outdoors or going to the kitchen). The application should be thorough and should cover all areas which are exposed to sun.
If you are being exposed to sun intermittently , for example your work consists of both desk jobs and sometimes you need to step up outdoors , you should use sunscreen every 2 hours. On the other hand if your work is continuously under the sun (any type of field work) , you need to reapply sunscreen every hour.
Recently there has been a debate regarding use of sunscreen and vitamin D synthesis as that requires exposure to UV rays. The current consensus among scientists is that you can safely continue to use sunscreen without any worry. If you however have a pre-existing vitamin D deficiency , you might consider vitamin D supplements or as instructed by your physician.
So , to sum up you should use a sunscreen which is broad spectrum , preferably water based , non-comedogenic and mainly contains physical blocking agents. However, if you have sensitive skin , acne or any other skin problems, it is better to see a dermatologist before choosing a sunscreen (also some sunscreens they prescribe are usually available only in pharmacies as they are of medical grade).
Unwanted black spots over face or any parts of our body are common skin problems. While sometime it can be due to a simple post acne spot, sometime may indicate a more complicated diseases like acanthosis nigricans.
Freckles - Scientific answer to all your questions
Melasma - Comparison of all treatment options
Acanthosis nigricans - your black neck can be a sign of Diabetes.
Dark circle - Different types and their treatment
Have a black spot or discoloration over anywhere over your body ? Get an instant free consultation powered by AI to know the common possibilities and some advice you can follow before visiting a dermatologist.
Have a question or comment? Please let us know.
Disclaimer: Online consultation in any form is not a replacement of an actual visit to a dermatologist, nor that is intended for. To stay updated with our service, like our facebook page, or for any query/suggestion send a whatsapp to 9932575251.
Join as dermatologist | Join as author
© 2022 by whatdx.com