Sunscreen are the agents which protect the harmful effect of the sun’s rays (UV+IR). They have always been the front line weapons in the armamentarium of a Dermatologist. A lot has been under discussion as to how to decide which sunscreen to prescribe and how to apply a sunscreen and when to apply it. There are a lot of factors to understand before you choose a sunscreen for yourself. Let’s understand them one by one.
SPF or Sun Protection Factor
It is the capability of a sunscreen to protect against the damaging effects of sun. A sunscreen with SPF 15 means that it block 93% of sun’s rays whereas SPF 30 means it block 97% of sun’s rays.
Sun emits a wide wavelength of radiation including ultraviolet(UV), visible light, infrared(IR). Both UV and IR radiations are damaging to the skin in their respective ways. A broad spectrum sunscreen means that it provides protection against both UV and IR rays.
Physical (inorganic) vs Chemical (organic)
Physical sunscreen are the heavy metal compound like Titanium and zinc oxides that block the radiation from reaching the skin by various mechanisms.
Chemicals sunscreens are especially formulated chemical compounds like avobenzone that undergo chemical alteration on sun exposure to prevent from sun damage.
Oral sunscreens are a recent trend in the medical field. These are the photo protective agents which when taken orally provide protection against the harmful effects of sun in a systemic manner. The compound that qualify in this group are Vitamin A, C, E, Selenium, Green tea .
How and when to apply sunscreen.
The most common mistake that we do is, applying sunscreen like a day cream. Applying lesser amount of sunscreen and less frequent applications are as good as no applications.
A sunscreen should be applied to all exposed parts of the body attest 20 minutes before sun exposure.
It needs to be reapplied every 2 hours.
The amount applied is also very important and for that we have “Teaspoon Rule”
1/2 teaspoon : Face & Neck
1/2 Teaspoon: Each arm
1 Teaspoon : Leg/Chest/ Arm
How to choose a sunscreen that suits you
- Confirm your skin type and duration of time that you spend outdoor before you choose a sunscreen.
- If you have any skin concern like acne or breakouts do visit your Dermatologist for the treatment of the same.
- People with oily skin can opt for a gel base sunscreen or lotion based sunscreen.
- People with dry skin should go a cream based sunscreen.
- People who like to wear make up or have pigmentation or blemishes can choose tinted or silicone based sunscreen according to skin tone.
- People with sensitive skin or have had a procedure done or who stay outdoor for longer duration may go for Physical sunscreen.
The bottom line is whatever you choose, please reapply it after a couple of hours, and consult your dermatologist to know better and if you have any queries.