Sun poisoning is a severe reaction to ultraviolet radiation that goes beyond ordinary sunburn. While a typical sunburn causes redness and tenderness that fades within about three days, sun poisoning produces more intense symptoms that last longer and can affect your entire body, not just your skin. The term isn’t a formal medical diagnosis but rather a catch-all for several conditions where sun exposure triggers a disproportionately harsh response.
How Sun Poisoning Differs From Sunburn
A regular sunburn is straightforward: your skin turns red, feels hot, hurts for a few days, and heals. Sun poisoning shares those skin symptoms but amplifies them and adds systemic effects. You may develop extensive blistering, swelling (especially on the face), nausea, fever, severe chills, headache, dizziness, or confusion. Dehydration is common because damaged skin loses fluid more rapidly than normal.
The distinction matters because sun poisoning sometimes requires medical intervention. A mild sunburn is uncomfortable; sun poisoning can leave you feeling genuinely ill, similar to having the flu on top of a burn.
Three Types of Sun Poisoning
The term “sun poisoning” actually covers a few different conditions, each with its own mechanism.
Severe Sunburn With Systemic Symptoms
This is the most common form. You’ve simply gotten far too much UV exposure, and your body responds with widespread inflammation. The burn itself is deep enough to blister, and the inflammatory response spills over into flu-like symptoms: fever, chills, nausea, and dehydration. People with large areas of blistered skin can lose enough fluid to need medical attention, particularly when the burn covers more than 20% of the body’s surface.
Polymorphic Light Eruption (PMLE)
PMLE is an immune-mediated rash that appears 30 minutes to several hours after sun exposure. It looks different from sunburn: dense clusters of small bumps and blisters, raised rough patches, and significant itching or burning. The rash typically shows up on skin that was covered during winter but exposed in warmer months, like the upper chest, front of the neck, and arms. Some people also develop fever and chills. PMLE tends to recur each spring or early summer and may gradually improve as the skin acclimates to sunlight over the season.
Solar Urticaria
This is essentially an allergic reaction to sunlight. UV radiation activates a substance in your skin that triggers your immune system to release histamine, producing hives within minutes of exposure. The welts look like raised, itchy bumps, similar to other types of hives, and they typically fade once you get out of the sun. Solar urticaria is less common than the other two forms. Diagnosis usually involves phototesting, where a doctor exposes small areas of skin to specific wavelengths of light to identify exactly which type of UV radiation triggers your reaction.
Medications That Raise Your Risk
Dozens of common medications make your skin more sensitive to UV radiation, dramatically increasing the chance of a severe reaction. The FDA lists several major drug classes that can cause photosensitivity:
- Antibiotics: doxycycline, tetracycline, and several fluoroquinolones
- Pain relievers: ibuprofen, naproxen, and other anti-inflammatory drugs
- Blood pressure and heart medications: thiazide diuretics like hydrochlorothiazide
- Cholesterol drugs: statins including simvastatin and atorvastatin
- Acne treatments: retinoids like isotretinoin
- Oral contraceptives and estrogens
- Antihistamines: including cetirizine, diphenhydramine, and loratadine
- Skincare products containing alpha-hydroxy acids (AHAs)
If you take any of these, you can burn faster and more severely than you’d expect. People on doxycycline for acne or a tick bite, for instance, are often caught off guard by how quickly their skin reacts to what seems like modest sun exposure.
Other Risk Factors
Fair skin burns more easily, but sun poisoning can happen to anyone with enough exposure. Spending time near water, sand, or snow increases your UV dose because these surfaces reflect light back onto your skin. High altitudes also mean more intense radiation. Being dehydrated before you go outside makes the systemic symptoms worse because your body is already low on fluids before the burn starts pulling more from your tissues.
How to Treat Sun Poisoning at Home
For cases that don’t involve emergency symptoms, home treatment focuses on cooling the skin, replacing lost fluids, and managing pain. Apply cool compresses, aloe vera gel, or a gentle moisturizing lotion to the burned areas. Cool colloidal oatmeal baths or calamine lotion can help with itching and discomfort. Over-the-counter anti-inflammatory pain relievers like ibuprofen reduce both pain and inflammation (assuming you’re not allergic or otherwise unable to take them).
Drink plenty of water. Burned skin loses moisture rapidly, and if you’re also experiencing nausea or fever, dehydration can sneak up on you quickly.
If blisters form, leave them intact as long as possible. Once they rupture on their own, cover the area with petroleum jelly to protect the raw skin underneath. Avoid applying corticosteroid creams like cortisone, which slow healing rather than help it. Also skip topical anesthetic creams, which can irritate already damaged skin.
Stay completely out of the sun until your symptoms have fully resolved. This isn’t optional; further UV exposure on compromised skin will deepen the damage and extend your recovery.
Recovery Timeline
A standard sunburn typically peaks at 24 to 48 hours and fades within three days. Sun poisoning takes considerably longer. The flu-like symptoms (fever, nausea, chills) may last several days, and the skin itself can take one to two weeks to fully heal depending on severity. Blistered skin heals more slowly and carries a higher risk of infection during recovery. Peeling is common in the later stages and can continue for a week or more after the initial pain subsides.
During recovery, watch for signs that a blister or open area is becoming infected: increasing redness that spreads outward, warmth, swelling, or pus. Infection is the most common complication of severe sun damage.
When Sun Poisoning Becomes an Emergency
Certain symptoms signal that your body is in serious distress and needs professional medical care. These include a fever with severe chills, facial swelling, confusion or feeling faint, rapid pulse or rapid breathing, pale or clammy skin, extreme blistering, eyes that are painful and light-sensitive, and signs of significant dehydration like dry mouth, no urine output, or sunken eyes.
If someone who has been in the sun develops a high body temperature and becomes confused or stops sweating, that’s heat stroke, which is a separate but overlapping emergency requiring immediate care.
Prevention
Use a broad-spectrum sunscreen with an SPF of at least 15, though SPF 30 or higher gives you a better margin of safety. Apply it 15 minutes before going outside to let it fully bind to your skin, and use about one ounce (roughly a shot glass) to cover your entire body. Reapply at least every two hours, and more often if you’re swimming or sweating.
Sunscreen alone isn’t enough for people who are especially prone to sun poisoning. Protective clothing, wide-brimmed hats, and UV-blocking sunglasses add layers of defense. Seeking shade during peak UV hours (roughly 10 a.m. to 4 p.m.) makes a bigger difference than most people realize. If you’re taking a photosensitizing medication, these precautions shift from optional to essential.