20% of the population worldwide is affected by sun allergy called polymorphous light eruptions (PLEs).

This is a skin condition that can significantly affect a person’s self-esteem. This is mostly due to the fact that it has a tendency to appear in body areas that are easily visible.

For example, most patients who suffer from PLEs have their whole arms, chests, lower legs, necks, and hands affected.

In this article, we will provide you an overview of PLEs and a better understanding of what causes it, how to treat it, and how you can avoid it.

Sun allergies explained

Sun allergy, also called as photosensitivity, refers to the skin disorder wherein the skin reacts abnormally when exposed to light, particularly, sunlight.

This disorder is not directly caused by sunlight and may have developed from pre-existing disorders and skin problems.

Some cases of sun allergies are greatly influenced by genetic factors. The exposure to the sun causes a reaction that is usually characterized by red rashes and small blisters.

Polymorphous light eruptions explained

Polymorphous Light Eruptions or PLEs are the most common form of sun allergy. This condition mostly affects young women from ages 20-30 who have fair and sensitive skin.

Most reported cases occur during summer and spring. The drastic change in temperature makes the skin sensitive and more susceptible to eruptions once exposed to sunlight.

Symptoms of this skin disorder usually show up after a day or two of being exposed to the sun. It takes the form of mild rashes and tiny pustules that looks like an acne breakout.

This can worsen if you continue to expose your skin to direct sunlight. On the bright side, this is not infectious and cannot be transmitted to another person by contact.


The causes

The exact causes of PLEs are yet to be fully understood.

But several studies suggest that this disorder may be a result of an altered skin compound that delays the skin’s functional processes.

The following are the most probable factors as to why PLEs occur:

  • UV Radiation. Exposure to UV Radiation, especially UVA, can weaken the function system of the T-cell and affect the skin’s cell protein production. This can provoke an abnormal reaction to UV Rays that develops into PLE. Sometimes, even sunblock-protected skin suffer eruptions from UV Radiation.
  • Reactive Free Radicals. UV Radiation can induce free radicals that radiate equally reactive compounds, these compounds can create oxidative stress and further result in skin cell damage.
  • Weak Cellular Defence.  Studies show that weakened cellular defense makes the skin incapable and extra sensitive to exposure to free radicals.
  • Photosensitivity. Sometimes, exposure to direct sunlight causes the skin’s immune function to over-activate. This results in flare-ups and lesions that often develop into PLE.
  • Genetic Factors. Some patients who suffer Polymorphous Light Eruptions have a family history of PLE.

The signs and symptoms

Symptoms of PLEs vary from person to person. The typical signs are usually characterized by the following:

  • Widespread rashes that are bumpy and red in color, can be painful
  • Small blisters that can easily be mistaken for pustules
  • Extreme itchiness and irritation on the affected areas

These usually appear in areas exposed to the sun like the neck, arms, back of the hands, lower legs, and chest.

  • Nausea
  • Headaches
  • Chills
  • Slight fever

Although quite rare, there are severe cases wherein hemorrhagic lesions appear. These lesions are raised skin that is bleeding underneath.

If you are experiencing the symptoms listed above, you should seek immediate medical attention. Visit your nearest doctor and ask for a diagnosis and proper treatment.



The best practices to do in order to prevent PLEs are the following:

  •         Use sunscreen every single day.
  •         Use sunscreen even when you are indoors and even if it’s winter time.
  •         Use sunscreen even on your lips.
  •         Avoid exposure to direct sunlight.
  •         As much as possible, limit your sunlight exposure.
  •         Avoid going outdoors between 11 AM and 4 PM.
  •         Wear protective clothing (long sleeves, pants, hats, caps, etc.) when going outdoors.
  •         Wear UV protective sunglasses.
  •         Scrutinize the ingredients list of a skincare product before using it on your body. Do a tiny patch test on your forearm first to see if it will trigger an abnormal reaction.


For mild cases:

PLEs have the tendency to be extremely distressing and unbearable.

You can visit a dermatologist and ask for a topical treatment (like soothing lotions or steroid creams) that can aid in minimizing the itchiness and irritation.

You can also take antihistamines to reduce the itching, but consult a doctor first. Use mineral sunscreens high in SPF at all times. This can alleviate the severity of your condition and prevent it from reoccurring.

For severe cases:

Your doctor may prescribe oral antihistamines and creams that contain corticosteroids. If these fail to improve your condition, you may be subjected to a series of prophylactic light therapy or phototherapy.

Phototherapy usually lasts up to three weeks. This treatment is done by cautiously exposing the skin to gradually increasing quantities of UV Rays.

This will enhance your skin’s tolerance to direct sunlight and gradually solidify your cellular defense over time until your PLEs are completely eradicated.

If phototherapy does not improve your condition, your doctor may prescribe a combination of medicines and PUVA.

Medical help

Symptoms of PLEs can be easily mistaken for other skin conditions. Instead, visit a medical professional and seek advice.

You may be subjected to undergo skin tests in order to determine whether or not you’re actually suffering from PLEs or a different skin problem with similar symptoms.

Do not self-medicate!

Other kinds of sun allergies

As previously mentioned, PLEs are the most common form of sun allergy.

But there are also other kinds of sun allergy that might share similar symptoms.

Like the Acne aestivalis or Mallorca acne.

This sun allergy is also caused by UV radiation but with the company of cosmetic ingredients that can be found mostly in emulsifiers and sun products.

There is also solar urticaria. This is rather rare and can be much more severe. Similar to PLEs and Mallorca acne, this is also caused by exposure to UV radiation.

However, this condition can arise from exposure to visible lights. This takes the form or large, itchy hives on skin areas commonly exposed to light.

For related topics, click on the link below.

Everything you need to know about Rosacea

Tips on treating psoriasis naturally 


Leave a Reply