Avoiding exposure to direct sunlight, especially during the early to mid-afternoon hours, is one of the most effective ways to avoid sun rash, although doing this is not always possible. Wearing lightweight clothing to cover the skin or using a sunscreen with a high sun protection factor (SPF) also can protect you. In addition to natural sunlight, tanning beds or sun lamps can cause sun rash and can be avoided to avoid the problem.
Once you have sun rash — an allergic reaction that appears as blotches, inflammation or small, itchy red blisters on skin that has been exposed to sunlight — you likely will develop it again. It sometimes is the body’s reaction to sunlight. Skin products or exposure to chemicals and prescription medications also can cause sun rash.
Sun rash can appear within an hour of being in the sun. The time it takes for a rash to appear depends on your level of sensitivity to the sun. Areas of the body not normally exposed to sunlight are particularly vulnerable to developing sun rash.
You can protect your skin from sun exposure by wearing clothing that keeps most of your body covered. During very warm weather, lightweight clothing can be worn. Clothing that is extremely lightweight or see-through, however, might not be enough to prevent sun rash, because the sun’s rays may be able to penetrate the lightweight fabric. A large hat and sunglasses can help keep the sun off your face.
A sunscreen with at least a 15 SPF can protect your skin while you are outside. An SPF of 15 means you should be able to stay in the sun up to 15 times as long as you would without sunscreen before having an adverse reaction. It is possible to reduce your SPF over time, if you are able to build up resistance to the sun.
A resistance to the sun can sometimes be developed through gradual exposure to sunlight over a period of time. This often is done under the guidance of a dermatologist or other medical professional. After extended periods with no sun exposure, it might be necessary to repeat the desensitization process.
If preventing sun rash doesn’t work, then there are treatments to lessen the symptoms. Home treatment often is sufficient for milder cases of sun rash. Aloe vera gel, cold towel compresses or hydrocortisone creams can be used to reduce swelling and redness. Over-the-counter pain relievers also can reduce discomfort.
Unless you have a severe reaction to sunlight, total sun avoidance usually is not necessary. For extreme cases, it is best to consult a doctor. For milder cases, some trial and error with various preventive measures usually is all that is needed to determine what works best for you.