Sunburns are complex and the precise mechanism that damages our skin is still being researched. Here’s what we know...
UV energy can damage molecules in the skin - most importantly DNA. The release of proteins and enzymes from molecular damage triggers the inflammatory process and dilates capillaries. It can take up to 6 hours for this response to manifest visibly as a burn. Damage can also destroy skin cells–one of the reasons why skin peels after a bad sunburn.
Discoloration of the skin can be immediate and/or delayed. Immediate darkening of the skin results from the redistribution of existing melanin and can fade within a few hours or days. Delayed tanning occurs when melanocytes produce new melanin. It requires a longer period of time and darkens with chronic exposure.
UV energy draws water from cells and contributes to dehydration of the epidermis. These dehydrated cells bind together and create a cellophane-like film over the skin surface. Dehydration increases the appearance of fine lines, enlarges the look of the pores, and traps oil in the skin, increasing breakouts.
In a summer’s time, the skin experiences epidermal hyperplasia, or the thickening of the epidermis in a effort to protect the body. Chronic damage increases skin thickness and the chance of nonmelanoma skin cancer. As the epidermis thickens, so does capillary damage. Inversely, UV energy damages collagen and elastin proteins, thinning the dermis. This damage contributes to laxity and wrinkle formation.
The body has mechanisms in play to repair damaged DNA after sun exposure. However, chronic UV radiation increases the probability that some of that damage will escape repair. This mutated DNA may eventually lead to skin cancer. Screen regularly for wounds that won’t heal and/or abnormal spots, lumps and bumps.