You’ve heard of sunburn, but have you heard of sun rash? As the sun shines down in the summer months, knowing how to recognize, treat, and prevent a sun rash can save you from ruining your outdoor plans. 

While everyone enjoys soaking up the sun, few things are more irritating than the harsh damage that occurs in the process. Having a sun rash is one of the most common consequences of overexposure to the sun’s ultraviolet light. 

Have no fear, WOW Skin Science is here to help. Let’s discuss sun rashes – how to treat them, prevent them, and more.

Table of contents: 

• What Is Sun Rash?
• Polymorphous Light Eruption
• Sun Rash vs. Sunburn: What’s the Difference?
• Ultraviolet Radiation
• Preventing Sun Rash with Sunscreen
• Treating Sun Rash
• Compress
• Hydrate
• Moisturize

What Is Sun Rash?

When exposed to the sun, there is a possibility that your skin may react poorly and develop a sun rash. Ultraviolet light is responsible for setting off this immune reaction. 

If you have light sensitivity, your chances of developing sun rash are heightened. However, other factors that may increase your likelihood of getting sun rash include living in regions with high sun exposure or high altitudes, and having a fair complexion.

Sun rashes take time to develop and may not be immediately visible. After the sun has made contact with your skin, signs of rash may begin to appear anywhere between a few hours to a few days later. Sun rash typically looks like a cluster of small, red, itchy bumps. 

The patches of skin may be raised, rough to the touch, and have a burning sensation.

Polymorphous Light Eruption

Arguably the most common form of sun rash is polymorphous light eruption (PMLE). The polymorphous light eruption is a reaction to the sun’s light, resulting in an itchy rash and swollen skin. 

This reaction is most likely to be triggered during the spring or summer seasons, but unlike an allergic reaction, it is not immediate. It is sometimes confused for a heat rash (known as prickly heat) with small red spots forming where sweat collects.

The polymorphous light eruption, also called sun poisoning, occurs due to unprotected exposure to the sun’s ultraviolet light for too long.

Other factors that increase your chances of developing this type of skin rash include living in a high-altitude area, near the equator, taking certain antibiotics, having a fair complexion, over-exfoliating with alpha-hydroxy acids (AHAs), and using certain herbal and citrus ingredients on your skin. The severity of your rash may be based on your skin’s sensitivity to the sun.

In addition to all the aforementioned sun rash symptoms — such as clusters of burning, rough, raised blisters on the skin — here are some other common reactions:

• Chills
• Fever
• Fatigue
• Dehydration
• Nausea
• Head and neck tension
• Dizziness
• Redness
• Discombobulation 

A polymorphous light eruption can appear more rapidly than other forms of sun rash, with symptoms on display as soon as thirty minutes post-sun exposure. 

So long as your polymorphous light eruption is not a severe case, the sun rash should go away within ten days. Otherwise, you must seek medical treatment from your healthcare provider.

Sun Rash vs. Sunburn: What’s the Difference?

Sun rash and sunburn are frequently confused for one another, and for a good reason. They look similar, share many symptoms, and both are caused by exposure to sunlight. 

There’s a difference between sun rash and sunburn, and understanding what separates the two is necessary for treating these skin conditions properly. 

Sun rash is a response from your immune system. Unprotected exposure to the sun’s ultraviolet light may cause your immune system to be overactive as it tries to defend your body – leading to an eruption of rashes on your skin. In fact, someone with solar urticaria, or sun allergy hives, may have hives appear mere minutes after sun exposure.

Sunburn, on the other hand, has little to do with your immune system. Rather than an immunological response, sunburn is exactly what it sounds like — a burn caused by the sun’s ultraviolet light.

Ultraviolet Radiation

Ultraviolet radiation is the source of most issues concerning sun damage, so what is it exactly? 

Ultraviolet radiation is a form of radiation with a shorter wavelength than visible light but longer than an X-ray. Ultraviolet radiation is notoriously emitted by the sun, though it can also come from artificial sources like tanning beds and certain lamps. 

This invisible light actually falls into two categories: Ultraviolet A and Ultraviolet B. To defend yourself against both sunburn and sun rash, you must be knowledgeable about the two categories of ultraviolet radiation and how they function.

• Ultraviolet A (UVA) has a longer wavelength. This length allows them to reach your dermis, the middle layer of your skin, where collagen, elastic tissue, and reticular fibers reside. This means that UVA light can negatively affect your skin on a cellular level. UVA is also linked to photoaging and premature skin aging.
• Ultraviolet B (UVB) is not as long in wavelength but has a higher amount of energy. Instead of reaching deeper into your skin, UVB targets the surface called the epidermis. UVB light is typically the cause of your sunburn. High exposure to UVB tends to result in skin damage that includes blisters. Blistering occurs when the areas between your various layers of skin become filled with fluid.

Preventing Sun Rash with Sunscreen

While the cause of sun rash may vary, there are precautions that you can take to minimize your chances of developing unwanted bumps on your skin. 

Sunscreen is the best defense for protecting your skin against sun damage. It is made with active ingredients that prevent the sun’s ultraviolet radiation from reaching your skin and causing further damage.

When selecting sunscreen, you need to choose between one with chemical or physical ingredients. Both perform the same task of keeping your skin safe from the sun, but do so differently.

• Chemical sunscreen contains ingredients like octisalate and avobenzone to absorb the sun’s ultraviolet light before it can harm your skin. 
• Physical sunscreen contains ingredients like zinc oxide and titanium dioxide that block and redirect the sun’s ultraviolet light before it can penetrate your skin. Physical sunscreen is generally deemed the safer option between the two for those with sensitive skin. 

Both physical and chemical sunscreens have been proven to work effectively, meaning that you are welcome to take your pick. Whichever sunscreen you decide to pick, it must have an SPF of at least 15. 

SPF stands for sun protection factor and indicates at what level your product may be able to defend your skin against the sun’s rays. More specifically, SPF indicates how long it can take for the sun to affect your skin. 

We recommend applying sunscreen with a minimum of SPF 15 roughly 30 minutes before leaving the house. In addition to SPF 15, you should use a sunscreen labeled “broad spectrum.” 

While you are welcome to choose between chemical or physical sunscreens, choosing a broad-spectrum sunscreen is non-negotiable. Broad-spectrum sunscreens are specifically designed to defend against both UVA and UVB rays to help prevent harm to your skin like premature aging.

If necessary, reapply your sunscreen throughout the day. To offer your skin some additional support, we suggest wearing sun-protective clothing if you know that you may be exposed to sunlight. This includes hats, collared shirts, long sleeves, and long pants for proper coverage.

Treating Sun Rash

As you wait for your sun rash to heal, there are methods for expediting the process and making yourself more comfortable along the way. Note that more severe cases may require phototherapy and timed UV light exposure to help reduce skin sensitivity.

• Compress

Many rashes, sun rashes included, are itchy and have a burning sensation. The application of cold compresses can help to minimize both of these pesky symptoms. Simply run a clean rag or washcloth under cool water and apply it to the affected area. 

Instead of a cold compress, you can also try ice packs or cool baths.

Another popular method for treating a sun rash is bathing in oatmeal. Oats have soothing properties that can help reduce the redness and itching that often accompanies these rashes. Apply colloidal oatmeal with a compress, add it to your warm bath, and soak for thirty minutes.

• Hydrate

When you develop a sun rash, fluids may be drawn from your body to the surface of your skin. While this step is essential to the healing process, it can contribute to dehydration. 

Hydrating the body and restocking your electrolytes can help boost your health and support your body as it combats your rashing. The general recommendation is that men should drink about 15.5 cups of fluids a day, and women should drink about 11.5 cups of fluids a day. 

Drinking enough water helps your body function properly. To help boost your water intake, you can also try incorporating the following foods into your diet:

• Watermelon
• Strawberries
• Zucchini
• Cucumbers
• Broccoli
• Lettuce
• Bell Peppers
• Cantaloupe

• Moisturize

Several over-the-counter creams — a popular option being hydrocortisone — are designed to soothe your skin and help alleviate the itching from your rash. Aside from these specialized creams, a gentle moisturizer can also help to relieve the dry, rough patches caused by your sun rash. 

There are several body moisturizers that you can use to help aid your skin back to health. For optimal hydration, we suggest the Shea & Cocoa Butter Moisturizing Lotion. This product is a fast-absorbing moisturizer suited for all skin types. Powered by natural vitamins and nutrients, our lotion can help to soothe irritated skin and aid in hydration.

While a bit of sun is a good thing, neglecting sunscreen can lead to short and long-term skin care problems. Remember to take the necessary precautions and practice healthy treatment options in the event you end up with a little more sun than you intended. 

Don’t forget to wear a wide-brimmed hat and avoid synthetic fragrances or products that cause a skin reaction.