Most people are familiar with the pain and discomfort of a sunburn. If you spend too much time in the sun (and don’t use enough sunscreen), your skin will become red, inflamed, sore, and may begin to peel.
But there’s another, less common, skin reaction that some people may experience when they are exposed to sunlight: a sun rash.
What is a Sun Rash?
A sun rash (medically known as a polymorphous light eruption) is a skin reaction that can occur in some people after exposure to sunlight. It typically appears as a reddish, itchy, raised area on the skin, and it happens for roughly 10-20% of people.
It is an autoimmune reaction, which means the body’s immune system mistakenly attacks healthy skin cells. In simple terms, it’s an allergic reaction to sunlight.
How is a Sun Rash Different From A Sunburn?
The high-energy ultraviolet radiation in sunlight can cause damage to the skin cells, which leads to the appearance of a sunburn. Repeated overexposure to sunlight can also lead to premature aging of the skin and an increased risk of skin cancer.
Sun rashes are not fully understood, but it is suspected by some researchers that they may result from an immune response to the metabolic by-products of damaged skin cells. In other words, the sun may damage the skin cells, and the body’s immune system reacts to that damage.
Sun rashes typically only appear in the bright sunny days of spring and early summer, with the first exposure to sunlight after a long winter. Sunburns can happen anytime, even on cloudy days and during the winter.
Are Sun Rashes Dangerous?
Sun rashes do not generally lead to any long-term damage or severe side effects, but they can be very itchy and uncomfortable for a week or two.
Most cases do not require treatment, though severe episodes may sometimes be treated with antihistamines, corticosteroids, or other medications.
Your best defense against a sun rash is to apply sunscreen any time you are going to be outside, especially mid-day when the sun’s rays are the strongest. Wearing protective clothing, such as long sleeves and pants, can also help reduce your risk of developing a sun rash.
Phototherapies involving controlled exposure to UV rays in wintertime may help prevent sun rashes from developing in the spring and summer.
Talk to your doctor if you have a rash on your skin that is not going away or if you have any other concerns about your skin and sunlight exposure. They will help you diagnose the cause and determine the best way forward.
