How to Treat Skin Rashes From the Sun

Updated April 17, 2017

A sun rash is also called heat rash, solar dermatitis or a sun allergy. It may occur on skin exposed to the sun immediately or two to four hours afterward. The causes of sun rashes are unknown, according to Harvard Medical School. They are most common in young women and fair-skinned people. A sun rash can be mild to severe, depending on the skin's sensitivity and the length of exposure. It may appear as small, red blisters, or larger red, blotchy patches of skin. It's sometimes accompanied by itching, burning and mild discomfort. You can take several steps to treat a skin rash caused by the sun.

Be certain the condition is indeed caused by sun exposure. It is crucial to identify the cause of any skin condition before attempting to treat it. Eliminate other possibilities for the rash, such as an allergic reaction from an ingested substance, or a photo-allergic reaction from chemical in a new skin care product.

Avoid scratching the affected area. Sun rashes are often itchy. Scratching the rash will only aggravate the skin condition, worsen inflammation and possibly cause the rash to spread.

Apply hydrocortisone cream. An over-the-counter hydrocortisone cream will relieve the itching. Store-bought oral antihistamines also relieve itching, but a cream is preferable for keeping the skin moisturised and has fewer possible side effects. For severe rashes, prescription cortisone creams are available.

Gently apply a cool, wet washcloth to the affected skin area to keep the skin moist. You can also mist the area with cold water from a spray bottle. Do this as often as possible until the rash disappears.

Soak in an Epsom salt bath. Add 2 c. of Epsom salt to a bathtub of lukewarm water. Epsom salt's healing properties can reduce swelling and draw toxins out of the body. Do not combine an Epsom salt bath with your everyday soaps and cleansers.

Apply aloe vera gel to the affected area about an hour before bed. Let the rash absorb a generous application of the gel. Make sure you use 100 per cent aloe vera gel, not a lotion that lists aloe as an ingredient. Aloe vera is soothing, contains anti-inflammatory and antibacterial properties, and is rich with nutrients that are absorbed by the skin and promote healthy cell functions.

Avoid tight clothing or anything that causes friction on the skin until the rash is gone. Wear light garments.

Avoid sun exposure, and use an ultra-high strength sunscreen such as a SPF 85 waterproof lotion when outdoors. The affected skin should not be exposed to the sun's rays at all, but this isn't always possible, especially if the rash in on the hands, face or neck. Rashes on the arms, chest or legs should be covered with sunscreen even beneath the light clothing.


To avoid rashes caused by the sun, always apply a high-strength sunscreen before going outdoors. The rash should subside within a couple of days if you cease sun exposure and treat it. Be aware of skin care products that may cause photoallergic reactions.

Things You'll Need

  • Hydrocortisone (or antihistamine)
  • 100 per cent aloe vera gel
  • Epsom salt
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About the Author

Isobel Washington has been a freelance journalist since 2007. Washington's work first surfaced in Europe, where she served as a restaurant critic and journalist for "LifeStyles" magazine. Her love of travel and culture inspired her first novel, which is currently underway. Washington has a 10-year career in marketing communication and holds a Bachelor of Science degree.