What Is Sun Poisoning?

Sun poisoning is a severe sunburn that develops after spending too much time in the sun or as a side effect of certain medicines. Often, sun poisoning results in painful, red, blistery skin and even flu-like symptoms.

Sun poisoning isn't exactly a medical diagnosis, Mary L. Stevenson, MD, a dermatologic surgeon at NYU Langone Health, told Health. Also, sun poisoning doesn't involve actual poison. Instead, it's a lay term for a really, really bad sunburn.

Whether you call it a severe sunburn or a case of sun poisoning, here's what you need to know about protecting and treating your skin.

Types of Sun Poisoning

There are different types of sun poisoning, including photoallergic or phototoxic reactions. The type of sun poisoning you develop depends on the cause and underlying risk factors. However, the most common cause of sun poisoning is simply spending too much time exposed to UV rays without the proper protection.

Photoallergic Reactions

Photoallergic reactions are a side effect of certain medicines that make your skin sensitive to the sun's UV rays and provoke an immune reaction. For example, topical drugs like isotretinoin used to treat acne raise the risk of photoallergic reactions. Likewise, oral medicines, like hormonal contraceptives, may increase your skin's sensitivity. This will look more like an allergic immune response—a rash—than a sunburn.

Phototoxic Reactions

Like photoallergic reactions, phototoxic reactions are also side effects of certain medicines, like retinoids. In contrast, the skin forms a rash that resembles a sunburn without significant UV exposure. A minimal amount of sun exposure can ignite a phototoxic reaction. Medicines that may cause a phototoxic reaction include tetracycline antibiotics and amiodarone. This will look more like an exaggerated sunburn.

Sun Poisoning Symptoms

Sun poisoning shares a few symptoms with sunburns. Namely, sun poisoning causes symptoms like:

• Redness
• Blistering
• Flu-like symptoms, such as fever, chills, or nausea
• Rash
• Skin peeling
• Pain where the skin was exposed to the sun's UV rays

Usually, you'll start to notice sunburn symptoms within a few hours of being out in the sun. In some cases, symptoms may not show up until a day later or longer.

If you have underlying immune disorders or skin conditions, you may also experience photodermatoses. Photodermatoses are "skin eruptions or rashes that are abnormal skin responses to sun exposure," explained Dr. Stevenson.

What Causes Sun Poisoning?

Sunburns happen when you expose your skin to the sun's UV rays for a prolonged time. Sunburns may occur with or without sunscreen or other protective measures. Also, artificial UV rays, like those found in tanning beds, cause sunburns.

Both UVA and UVB cause sunburns, but UVB rays damage your DNA. When your DNA tries to repair itself, the body releases inflammatory markers. In response, your skin generates a red, painful sunburn. 

Sun poisoning is a severe sunburn. The time you spend outside, your location, the time of day, and the weather may increase your risk of severe sunburns. For example, if you spend an afternoon outside at high altitudes, you may develop a more severe sunburn than usual.

Also, certain medicines make your skin more sensitive to the sun's UV rays than usual. Other treatments may cause sunburn-like rashes.

Risk Factors

Anyone can develop a sunburn or sun poisoning. Still, certain factors increase your risk of severe sunburns, including:

• Time of day
• Ozone depletion
• High altitudes 
• Weather, such as clear skies
• Close proximity to the equator 
• Sun lamps and tanning beds
• Outdoor exercise 
• Light skin that burns easily
• Certain medicines

How Is Sun Poisoning Diagnosed?

Mild sunburns usually don't require a visit to a healthcare provider for a diagnosis. In contrast, for sun poisoning, a healthcare provider may assess the severity of your sunburn.

Typically, a healthcare provider will conduct a physical exam and assess any redness and pain. They may also feel your skin to check for warmness, swelling, or itchiness. Based on the severity of those symptoms, the healthcare provider can tell the extent of your sunburn. 

Flu-like symptoms link to severe sunburns. Further, blisters may mean that your sunburn is deep.

Treatments for Sun Poisoning

The very first thing to do when you notice a sunburn, severe or otherwise, is to get out of the sun. Then, assess the damage. 

"Extreme blistering or symptoms of dehydration require a visit with a [healthcare provider] who can examine, assess, and treat the symptoms and, in severe cases, treat the dehydration," said Dr. Stevenson.

If the blisters cover a large portion of your body, see a healthcare provider right away. In some cases, you may need to go to the emergency room, especially if you have flu-like symptoms or are dehydrated. Healthcare providers may treat sun poisoning with intravenous (IV) fluids for rehydration. A specialist may provider additional care in a burn unit.

A mild sunburn is probably something you can handle at home. Take note of the following tips to treat a mild sunburn:

• Cool down your skin: Take cool showers or use cool compresses to help relieve some pain and lower your skin's temperature.
• Use aloe vera: Gels made with aloe vera "can provide a cooling effect that can ease symptoms," noted Dr. Stevenson. 
• Consider milk compresses: "Cold milk compresses can also provide relief, as the lipids in milk can be soothing to the skin," said Dr. Stevenson.
• Take pain relievers: An over-the-counter (OTC) pain reliever like ibuprofen can alleviate pain until symptoms subside, usually within a few days. 
• Try a high-dose of vitamin D: Research suggests that a high-dose of vitamin D can help mitigate the inflammation caused by a sunburn. More research is needed into the appropriate dosage, so talk to a healthcare provider before adding any supplements to your diet post-sunburn.
• Drink plenty of water: Sunburns and sun poisoning can be dehydrating. "After being in the sun for too long, hydration is key, so make sure to drink up," said Dr. Stevenson.
• Don't pop blisters: As you heal, ensure that you don't touch any blisters. Popping blisters increases the risk of infection.
• Cover up: Wear protective clothing while outdoors to help your skin heal and prevent future sunburns.

How To Prevent Sun Poisoning

Since sun poisoning at its core is a severe sunburn, following standard sun protection tips will help avoid it.

Cover exposed skin with a water-resistant, broad-spectrum sunscreen with an SPF of 30 or above, even on cloudy days. Sunscreen with an SPF of at least 30 protects you from UVA and UVB rays.

Make sure you're using about a shot glass-size amount of sunscreen for your body and a teaspoon-size amount for your face and neck, Dr. Stevenson previously told Health. Then, reapply every two hours. Also, don't forget to put sunscreen on sneaky places that are easy to miss, like your scalp and ears.

Consider wearing sun-protective clothing with UPF (like SPF for fabric) built-in. However, clothing that covers exposed skin, wide-brimmed hats, and sunglasses work well, too. Limiting sun exposure when UV rays are their strongest, typically between 10 a.m. and 4 p.m., is also key.

Lastly, never use sun lamps or tanning beds, which significantly increase the risk of skin cancer. Being in a tanning bed for as little as 15 minutes equals spending a whole day in the sun.

Comorbid Conditions

Sunburns, especially severe and frequent ones, increase the risk of skin cancer. Having five or more sunburns that blister between the ages of 15–20 raises the risk of non-melanoma skin cancer by 68%. In contrast, the risk of melanoma increases by 80%. Melanoma is a severe type of skin cancer.

Living With Sun Poisoning

With treatment, sun poisoning eventually heals. However, you should consult a healthcare provider right away if you have any of the following symptoms:

• Flu-like symptoms, like chills, fever, nausea
• Rash
• Dizziness
• Labored breathing 
• Increased heart rate
• Being very thirsty but not urinating
• Pale skin that is clammy or cool to the touch
• Sensitivity to light
• Painful blisters

Treatments, such as taking cool showers and staying hydrated, can help you feel comfortable while recovering from sun poisoning. Also, taking precautions to protect yourself from future sunburns is one of the most important ways to decrease skin cancer risk.

A Quick Review

Sun poisoning is a severe sunburn, which occurs after spending too much time in the sun. In some cases, sun poisoning develops as a side effect of certain medicines. 

Often, sun poisoning results in painful, red, blistery skin and even flu-like symptoms. Cooling your skin, taking pain relievers, and staying hydrated can help relieve severe sunburn symptoms. 

Ensure that you're taking precautions to protect yourself from future sunburns and lower your skin cancer risk.