Have a Sun Rash? 3 Dermatologists Weigh In on What to Do

According to Dr. Jaliman, a sun rash is an allergic reaction. "[It's] also known as sun poisoning or sun allergy and is an allergic reaction to exposure to the sun's ultraviolet rays," she said.

Dr. Nussbaum added that it may show up a little while after you've been in the sun. "It typically starts 30 minutes to a few hours after exposure to sunlight – and it may itch or burn."

According to Dr. Bhanusali, there are several causes of the red, splotchy skin. "It's most commonly another name for polymorphic light eruption (PMLE), which is a reaction that people have to the sun itself," he said.

Although less common, he also has several other explanations for the rash. "Some people can have autoimmune conditions that can cause an inflammatory-like reaction like burning on the cheeks when in the sun," he said. "There are some patients who have allergies to ingredients in sunscreen as well."

Wondering if you can be affected? "It is more common in females with light skin or with a history of a sun rash, but can happen to anyone," Dr. Nussbaum said.

Dr. Jaliman's advice for preventing sun rashes also serves as wise instructions for protecting your skin from UVA and UVB rays. "Minimize your sun exposure by avoiding the sun during the peak hours of 10 a.m. and 3 p.m.," she said. "Always wear at least SPF 30, a wide brim hat, and protective clothing with UPF."

Dr. Jaliman suggests a few at-home treatments to ease your rash. "You can soothe it with aloe vera, use over-the-counter hydrocortisone, and take an antihistamine," she said.

However, if it doesn't go away, both she and Dr. Bhanusali recommend you head to a dermatologist. "Often if it is itchy, your derm may give a topical steroid to relieve symptoms," he said.