Kallgren Dermatology is staffed by highly qualified dermatologists and has been located in Boulder since 2006. We treat many types of skin disorders but also care about sun damage prevention. To that end, we carry EltaMD sunscreens. These sunscreens broad spectrum sunscreens, meaning they protect against UVA and UVB rays.

In this blog series we’ve been covering sunscreens and how they work. This week we are going to cover what to do if you forget your sunscreen or didn’t reapply after swimming.


Oops! Sunburn!

It happens to all of us. We think we will be just a few minutes in the sun and end up being there much longer than any protection we have on can help us. Your skin feels warm and maybe you feel tightening of the skin too.

What happens when you get a sunburn?

When UVB rays hit your skin, they stimulate specialized cells called melanocytes to release melanin. Melanin is the pigment that, when enough has been secreted, gives you a tan, or freckles.

Does UVB damage skin?

UVB is also considered a mutagen, or something that causes a change in DNA. Some mutation in cells cause cancers to form.

How fast can UVB damage skin?

It is said that it takes only 10-15 minutes for DNA damage to occur from UVB exposure.

Does UVA damage skin too?

Yes, the damage from UVA is invisible because it doesn’t cause a sunburn but it does cause damage. UVA rays go deeper into the skin and damage cells called keratinocytes in the basal layer of the skin. This is where most skin cancers occur.


It is best to protect yourself against both UVA and UVB rays by using a broad-spectrum sunscreen such as EltaMD sunscreens. Call to make an appointment with Kallgren Dermatology.