What is a sunburn?
The outer layer of the skin gets its color from a dark pigment called melanin. When the skin is exposed to Ultraviolet (UV) rays, the body protects itself by accelerating the production of melanin—this extra melanin darkens the skin, creating a suntan. A suntan is the body’s way of blocking UV rays, but most people don’t produce enough melanin to protect the skin from burning when it’s overexposed to UV light, leading to painful, itchy sunburns.
If you’ve ever had a sunburn, you’re probably familiar with the symptoms: reddening of the skin; skin that feels hot to the touch; pain, tenderness, and itching. But why exactly does the skin react this way and how do you know if you need to see a doctor about your burn?
Explaining the Pain
The energy from ultraviolet radiation can damage molecules in the skin, most importantly, DNA (deoxyribonucleic acid)—the long molecule that contains our unique genetic code. The damage to these molecules leads to the production of certain kinds of proteins and enzymes, which in turn cause blood vessels to dilate and leads to inflammation—that’s why your skin gets sore and red when you burn. The warmth of sunburnt skin can be attributed to an increase in blood flow to the affected area. Your skin may also peel as your sunburn heals as this is your body’s way of getting rid of damaged cells that could potentially become cancerous.
When You Should See a Doctor
If your symptoms last for more than a few days or get worse, you should probably speak to your doctor or dermatologist. Seek medical attention right away if you experience painful blisters, fever, nausea or vomiting with your sunburn.
Sources:
https://www.mayoclinic.org/diseases-conditions/sunburn/symptoms-causes/syc-20355922
https://www.scientificamerican.com/article/what-happens-when-you-get/