Do you get blisters when you go out in the sun? Let's talk about this sun allergy (Polymorphous Light Eruption - PMLE)

Imagine that you came home after going out for a bit in the morning. A few hours later, you notice small red blisters on your neck and arms that are itching a lot. You might think that this is because you were exposed to the sun, but this is not always the case. It only happens sometimes. This is the condition we are talking about today, PMLE, or as many people call it, 'sun allergy'. This is not as dangerous as you might think, but it is very uncomfortable. So let's find out more about it.

What exactly is PMLE?

Simply put, Polymorphous Light Eruption (PMLE) is a common skin condition that occurs after skin is exposed to ultraviolet (UV) rays from the sun. It is like an allergy.

This name may sound a bit too scientific, but its meaning is very simple.

• The word "polymorphous" means "of different shapes." This means that these blisters and spots can look different to each person. For some, they may look like small red blisters, for others, they may look like large red spots, and for some, they may even look like blisters.
• "Eruption" means "sudden appearance." This means that these blisters can appear suddenly, within a few hours of sun exposure, perhaps as little as 30 minutes.

Some people call this condition "sun allergy." That's a good word to describe it, because it's actually an abnormal response by the body to sunlight.

What causes this sun allergy?

Doctors still haven't found a 100 percent definitive cause for this, but the current accepted view is that it's caused by a change in the way our body's immune system works .

Think of it this way. When UV rays from the sun hit our skin, a certain compound in our skin changes because of those rays. Then our body's defense system, the immune system, mistakenly identifies this newly formed compound as an 'enemy' or 'stranger.' Then it starts to fight against it. As a result of that reaction, the skin becomes red, blistered, and itchy.

What kind of light rays affect this?

There are two types of ultraviolet light in sunlight.

1. UVA rays: These penetrate deep into the skin. These UVA rays are responsible for 9 out of 10 cases of PMLE.

2. UVB rays: These damage the surface of the skin and are responsible for sunburn.

That means that the main cause of PMLE is UVA rays. These rays can come not only from sunlight, but also from some artificial light sources, especially tanning beds used to tan the skin.

Who is more likely to develop this condition?

PMLE is a condition that can affect anyone, regardless of age, race, or gender. However, some people are more likely to develop it. Let's take a look at who they are.

What are the symptoms of PMLE?

The main symptom of PMLE is red, itchy blisters or spots. These usually appear on sun-exposed areas. These spots/blisters can come in different shapes and sizes for each person.

These symptoms usually subside within two to three days. However, if you are exposed to the sun again while the blisters are still there, the condition may worsen and last longer.

Where on the body do these blisters/spots appear most often?

These can appear anywhere exposed to the sun. But surprisingly, they are very rare on the face. This may be because the face is constantly exposed to the sun, so there is a certain amount of adaptation. These blisters are most commonly seen on:

• Upper chest (near the neck)
• Neck
• Hands
• Legs

How do I know for sure if this is PMLE?

If you get blisters like this after going out in the sun, it's not a good idea to decide for yourself, "This is PMLE." There can be other skin diseases and other serious conditions that show similar symptoms.

Therefore, it's best to definitely see a doctor and get checked out.

The doctor usually does:

1. You will be asked details: How long has this been going on, how often does it come back after being in the sun, and whether anyone in your family has it.

2. Examine the skin: Carefully examine the nature of the blisters.

3. Perhaps if necessary:

• Skin Biopsy: A very small piece of skin can be taken and sent for examination.
• Blood tests: You may be asked to take a blood test to check for other diseases that show similar symptoms, for example, autoimmune diseases such as lupus erythematosus.

How to treat and prevent it?

The best thing to do for PMLE is to prevent it rather than treat it. Most of the time, these blisters go away on their own within a week or two. But the itching is very annoying.

Prevention is best!

• Avoid harsh sunlight: Minimize exposure to harsh sunlight, especially between 11 am and 3 pm.
• Use sunscreen: This is a must. Since the sun is harsh in our country, it is very important to use a sunscreen that has at least SPF 30+ and is labeled 'broad-spectrum' . Broad-spectrum means that it protects you from both UVA and UVB rays. Apply it thoroughly to all exposed areas about 20 minutes before going out.
• Wear protective clothing: Cover your skin with things like long sleeves, long pants, a big hat, and sunglasses.

"Skin Hardening"

For some people, this is something they can do on the advice of a doctor. This is also called ``phototherapy''.

What this does is gradually, in a controlled manner, accustom your skin to UV rays. It's like a vaccine. By exposing it little by little, you give your skin a 'training'. Then, when suddenly exposed to a lot of sunlight, your body won't be alarmed.

What to do if you get blisters?

If blisters appear and the itching is severe, the doctor will prescribe treatment for you.

• Topical Corticosteroids: Creams applied to the skin. These reduce itching and redness.
• Antihistamines: Tablets. These can control itching.
• Oral Corticosteroids: In severe cases, your doctor may prescribe oral steroid pills, such as prednisone. These may be prescribed in advance, especially if you are going on vacation to a sunny location.
• Other medications: There are also cases where medications like `(Hydroxychloroquine)` are used for very severe, difficult-to-control PMLE conditions.

Will this condition continue? When should I see a doctor?

PMLE is a recurring condition. Some people may have it for years. But the good news is that for most people, the severity of the condition gradually decreases over time.

You should see your doctor:

• If you notice unexplained blisters, spots, or changes to your skin.
• If you always get blisters like this after going out in the sun.

Can PMLE cause skin cancer?

This is a big question and fear for many people. The answer is, no.

PMLE is a non-cancerous (benign) condition. These blisters do not increase your risk of developing skin cancer.

But, the important thing here is that PMLE is caused by UV rays. Long-term exposure to those UV rays is a major cause of skin cancer. That means that every step you take to prevent PMLE (wearing sunscreen, staying out of the sun, wearing protective clothing) will also help protect you from skin cancer. So it's a win-win situation!

Sun allergy, PMLE, sun blistering, skin itching, UV rays, sunscreen, skin diseases, polymorphous light eruption