If you have light-colored skin, you can get sunburns very easily. But if you have a sun allergy (photosensitivity), your skin will get inflamed and itchy even faster.
If you notice hives on your skin, or if it gets itchy and inflamed after spending just a few minutes in the sun, you might be suffering from a sun allergy.
So what is a sun allergy or an allergic reaction to sun rays? And how is this even possible? I’ll try to explain to you everything related to sun allergies. Just keep reading!
What Is A Sun Allergy?
Sun allergy is also called photosensitivity in clinical terms. It’s a “normal” reaction of your body to ultraviolet light (both natural sunlight and artificial light).
Your immune system is the one that triggers those allergic reactions. It searches your entire body for dangerous substances (allergens). If any of them are found, your body produces molecules called antibodies.
Antibodies are the ones that cause symptoms such as inflammation and itching. That’s because they’re trying to fight the allergens and, at the same time, inform you that something is wrong with your body.
There are numerous types of antibodies, and each of them can recognize a single allergen. So whether you have a sun allergy and/or other allergic reaction or not, it all depends on the type of antibodies you have.
The multiple types of antibodies that might or might not be present in you are the reason why you and your friend/sibling may have different allergic reactions.
How Does It Differ From A Sunburn?
Sunburns are more frequent in people with sensitive skin and can even lead to damaging the DNA in the affected areas.
Sun allergies do not depend on the skin type and don’t involve any DNA damage. They can be spontaneous and can be accelerated by drug or chemical exposure. Also, diseases like lupus can lead to sun allergy as a side effect.
As you can see, there are many factors that can cause an allergic reaction to the sun. But a sunburn can only be caused by direct exposure to the ultraviolet rays of the sun.
Types Of Sun Allergy
Here are the most common types of sun allergy:
1. Chemical Photosensitivity
This is a sun allergy that can cause a reaction on the skin that looks like a bumpy rash or a sunburn.
Chemical photosensitivity is triggered by the drugs or the chemicals found in your foods, medication, or cosmetics when your skin is exposed to ultraviolet light (this also includes artificial light beside the natural sunlight).
There’s a slight difference between phototoxicity and photoallergic reactions. So let me clear this for you.
When a drug or a chemical agent absorbs ultraviolet light, it produces compounds that can cause skin inflammation and even long-term damage to the skin. This process is called phototoxicity.
Now, on the other hand, photoallergic reactions are less common and less dangerous and occur when ultraviolet light turns a substance into an allergen.
In both cases, drugs or chemicals is the culprit. They react differently under sunlight, but both can cause a sun allergy.
3. Solar Urticaria
If you experience hives every time you expose your skin to the sunlight, then you most likely suffer from a sun allergy called solar urticaria.
Usually, the hives don’t last more than two hours but they reappear each time you expose your skin to ultraviolet radiation.
The causes of solar urticaria aren’t clear, but scientists believe that it’s due to the photoallergens that occur naturally in the skin.
4. Polymorphous Light Eruption (PMLE)
This is another type of sun allergy that causes the formation of red, itchy bumps on the skin.
The bumps appear immediately after exposing your skin to ultraviolet radiation (sunlight and artificial light) and usually disappear within days.
As the name suggests, PMLE is a light eruption. And with every new exposure, the severity of the reaction decreases.
PMLE sun allergy is most often experienced by people from northern countries when the summer season occurs.
Medication That Can Cause Sun Allergy
Here is a comprehensive list of the medications that can cause photosensitivity:
- Alpha-hydroxy acids found in cosmetic products;
- Diuretics such as bumetanide, frusemide, and hydrochlorothiazide;
- Antibiotics such as ciprofloxacin, doxycycline, ofloxacin, levofloxacin, trimethoprim, and tetracyclines;
- Sulfonamides (most of them are also antibiotics) such as acetazolamide, sulfamethizole, sulfadiazine, sulfamethoxazole, sulfasalazine, sulfapyridine, and sulfisoxazole;
- Ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ketoprofen, naproxen, piroxicam, and celecoxib;
- Antifungals such as voriconazole, griseofulvin, and flucytosine;
- Oral contraceptives;
- Estrogen supplements;
- Retinoids such as isotretinoin and acitretin;
- Antipsychotics such as phenothiazines (fluphenazine, chlorpromazine) and thioxanthenes (chlorprothixene);
- Type 2 diabetes medication (hypoglycaemics) such as sulfonylureas, which include glyburide and glipizide;
- Antihistamines such as diphenhydramine, cetirizine, loratadine, cyproheptadine, and promethazine;
- Targeted therapies such as dabrafenib, vandetanib, imatinib, and vemurafenib (50%);
- Cholesterol-lowering drugs such as atorvastatin, simvastatin, pravastatin, and lovastatin;
- Psoralens such as trioxsalen, methoxsalen, and 5-methoxypsoralen;
- And other drugs such as enalapril, tranquilizers, amiodarone, hydroxychloroquine, diltiazem, dapsone, quinidine, and quinine.
Besides medication, there are other external agents that can trigger chemical photosensitivity:
- Sunscreens containing salicylates, benzophenones, cinnamates, oxybenzone, cyclohexanol, or para-aminobenzoic acid (PABA);
- Different photosensitizing fragrances such as musk or 6-methyl coumarin;
- Anti-microbials such as chlorhexidine (Peridex), dapsone (DDS), or hexachlorophene (Septisol, Phisohex);
- Chemotherapy drugs used for cancer treatment such as 5-fluorouracil (5-FU, Efudex, Carac, Fluoroplex);
- Coal tar.
For a complete overview of the medications that can cause photosensitivity, take a look at this article.
Foods That Can Cause Sun Allergy
Did you know that some of your favorite foods that you eat regularly can also lead to sun allergy? These include:
- Mango peel;
- And parsnips.
The compounds found in these foods can cause a bad reaction in your skin when exposed to sunlight.
For example, if you touch a lime and then expose your skin to the sunlight, you may experience margarita dermatitis which manifests as an itchy burn or rash and can be quite painful.
The same thing can happen after touching celery or parsley and exposing your skin to the sun.
Other food items that can contribute to photosensitivity are artificial sweeteners. Look for cyclamates, calcium cyclamate, or sodium cyclohexylsulfamate on your food labels.
Some popular herbs such as Ginko Biloba and St. John’s Wort may also cause you a sun allergy.
Now, on the other hand, there are fruits and veggies that promote healthy skin and can help you protect your skin from damage. These include blueberries, watermelon, nuts, seeds, leafy greens, carrots, cauliflower, and green tea, among others.
Sun Allergy Treatment And Prevention
The most practical treatment for any disease is prevention. The same goes for sun allergy or photosensitivity.
Here’s what you can do to prevent a bad reaction on your skin:
1. Avoid Overexposure To Sunlight
Stay away from direct sunlight, especially during peak hours. At midday, between 10 AM and 4 PM, the ultraviolet radiation of the sun is huge.
If you want to protect your skin from blisters, rashes, burns, and other allergic reactions, you must avoid exposing your skin to sunlight during this time interval.
2. Avoid Sudden Exposure To Lots Of Sunlight
You might experience sun allergy symptoms in the spring or summer when there is more sunlight outdoors.
To avoid this, keep your skin away from sudden exposure to lots of UV radiation and gradually increase your outdoor time. This way, your skin has enough time to adapt to sunlight.
3. Protect Yourself From The UV Rays
Your skin isn’t the only organ you must protect from the UV rays. Too much light can also affect your eyesight. So wear sunglasses whenever you go outside on sunny days.
Now, getting back to our skin, protective clothing is mandatory. Think long-sleeved shirts and wide-brimmed hats. They can protect your skin from sun exposure and sun allergies.
Also, avoid sheer fabrics because UV rays can pass through them and eventually damage your skin.
4. Use Sunscreen
If you want to properly protect your skin during the summertime (and not only), you must use sunscreen with a sun protection factor of at least 30 (SPF 30).
Apply sunscreen on every inch of skin you plan to expose to sunlight. Then reapply it every 2-3 hours, or even more frequently if you’re perspiring or swimming.
Again, stay away from any sunscreen or lotion that contains salicylates, benzophenones, cinnamates, oxybenzone, cyclohexanol, or para-aminobenzoic acid (PABA).
5. Avoid Known Triggers
This part is simple; you just need to avoid any substance, food, drug, or medication that can trigger a skin allergy.
Pay attention to the list of medications, foods, and external agents that get into contact with your skin. Who knows, it might be the limes you put in your drinks that trigger your skin reaction.
Now, not getting into contact with limes is easy, but what about a medication that your doctor prescribed you? You can’t just ditch it because your skin “tells” you that.
So the wise thing to do here is to ask your doctor for help. He/she knows whether you should get rid of the allergy-causing medication, or should take one more for your allergy.
6. Eat Carrots
Studies show that carrots, more precisely the β-carotene they contain, can help your skin against UV radiation.
So by consuming carrots regularly, you’re less likely to suffer from sunburns or skin allergies. However, consuming too many carrots can alter your skin color.
As you can see, there are a few useful tips to help you prevent your skin from getting an allergy. But how about treatments for those who already have an eruption?
Well, as much as I would love to share with you some methods to treat sun allergy, I won’t. That’s because if you see something unusual on your skin, you MUST see a dermatologist.
It’s that simple: protect your skin from the sunlight with long-sleeved shirts, sunscreen, and carrots. And if you have symptoms of a skin allergy, contact your doctor.