SUN BURN

Overexposure to the sun is by far the leading cause of skin damage, with consequences ranging from mild sunburn to premature aging and even skin cancer.

Most sunburns are classified as,
-First degree
-Second degree &
-Third degree

first degree are limited to the epidermis, second degree extends to the dermis and third degree will damage both layers of skin, underlying nerves and subcutaneous tissue, are rare.
They occur manly in babies and newly born. Damage depends upon intesity of ultra violet rays.

UV radiation has two components:
-The shorter UVB rays, which are responsible for most burns &
-Longer UVA rays, which are involved more in sun-tanning
both causes skin damage as well as promote skin cancer

over exposure to UV rays also encourages actinic keratoses; these are scaly lesions that may be pre-cancerous.

The tanning process is the body's way of protecting the skin from the sun's damage. Pigment producing cells send an increasing amount of melanin to the skin's surface to block the harmful incoming rays. Thus fair-skinned, blue eyed people who do not readily tan are the most vulnerable to sunburn.
Those with dark skin are also susceptible, but their heavier layer of melanin helps protect them against sunburn.