Polymorphous Light Eruption

1 What is Polymorphous Light Eruption?

Polymorphous light eruption or polymorphic light eruption (PLME) is an itchy rash caused by sun exposure in people who have developed sensitivity to sunlight or photosensitivity.

It is red with slightly raised or tiny bumps patches of the skin. When a person’s exposure to sunlight increases such as in summer or spring, polymorphous light eruption occurs.

PLME often reoccurs each year after the first incident though repeat episodes are less likely as the summer progresses.

Sometimes PLME will go away without any treatment but there are medicines available to treat severe or persistent cases and preventive measures to protect the skin to prevent recurring episodes of PLME.

2 Symptoms

Itchy rash is the main symptom of polymorphous light eruption.

Eruption refers to the rash that appears after exposure to the sunlight, sometimes within minutes to hours or within a couple of days.

The rash will be seen in body parts which are covered in winter but exposed on summer such as front of the neck, arms and upper chest.

The rash may include:

  • redness;
  • raised rough patches;
  • burning or itching;
  • swelling and blistering;
  • dense cluster of small bumps.

Some people will experience

and this may be related to sunburn.

Consult your doctor if you have any rash like from a poison ivy or allergy or if the rash is painful, accompanied by fever or widespread.

3 Causes

There is no exact cause of polymorphous light eruption. The rash is developed to people who have sensitivity to sunlight and are exposed ultraviolet radiation from the sun or other sources like tanning lamps and beds.

This is called photosensitivity that produces rash and inflammation because of the sunlight induced immune system activity. A wavelength of sunlight in a range too short for our eyes to see is called UV radiation and it reaches the earth that is divided into 2 wavelength brands such as ultraviolet A (UVA) and ultraviolet B (UVB).

If you have photosensitivity you can react to both of these. UVA penetrate glass while UVB does not.

PLME have predictable features such as:

  • after the first one or two exposures to sunlight after a long period of no exposure an episode will occur;
  • other people will be less sensitive after several years and may be they will not have recurring episodes;
  • most of the time it will occur on summer;
  • after the first episode there will be additional episodes annually like every summer or spring.

4 Making a Diagnosis

Consult your doctor and he may refer you to a dermatologist that specializes in skin diseases to receive a diagnosis of polymorphous light eruption.

You should be prepared when visiting your doctor. Bring a notebook and write down the symptoms you are experiencing and for how long. You can also write down the recent changes and major stresses in your life as well as the supplements, vitamins and medications that you are taking.

Prepare a list of questions, some of the questions that you can ask your doctor include:

  • What is causing my symptoms?
  • Is this temporary or long term?
  • What tests do I need?
  • What treatments are available?
  • Do they have possible side effects?
  • Do I have any restrictions to follow?
  • Is there a generic alternative to the medicine that you are going to prescribe me?
  • What websites can you recommend?

Your doctor will also ask you questions such as:

  • When did the rash occur?
  • Is it painful?
  • Is it itchy?
  • Have you had a fever?
  • Do you have any other symptoms?
  • Did you recently have anew medication?
  • Did you use make-up or perfume in the area of the rash?
  • In, the past have you ever had a rash?
  • Do you use sunscreen?
  • Have you used tanning lamps or beds?
  • Have you been exposed to sunlight longer than before?

While waiting for the appointment with your doctor, avoid sun exposure or when going out use a broad-spectrum sunscreen with an SPF of at least 15.

Your doctor will first conduct a physical exam to check your overall health and to examine the rash and your skin’s condition. He will also order some tests such as:

  • Skin biopsy - he will get a small sample of the rash to remove a tissue from your skin to see if there are other conditions that might be causing the rash,
  • Blood tests – to rule out other conditions,
  • Phototesting – your doctor will exposed some of your skin to UVA and UVB to recreate the problem.

If your skin reacts to UV radiation you have photosensitivity or may have PLME or other light induced disorder. Your doctor may also rule out other disorders such as:

  • Solar urticaria – sun-induced allergic reaction that can produced hives with red, raised, itchy welts on your skin which can appear after a few minutes of sun exposure and will last for minutes to hours, this is a chronic condition that can last for years,
  • Chemical photosensitivity – some chemicals that came from drugs, perfume, pant products, medicated lotions. Your skin will react after coming into contact with these chemicals and at the same time exposed to sunlight,
  • Lupus rash – inflammatory disorder that can affect body systems.

5 Treatment

The polymorphous light eruption will go away within a few weeks or more but if you are bothered by it, you can ask your doctor for treatments such as:

  • Anti-itch cream – cream that contains at least 1 percent hydrocortisone or corticosteroid cream if it is severe,
  • Pain relievers – such as Ibuprofen (Advil, Motrin IB), naproxen sodium (Aleve) and acetaminophen (Tylenol) to reduce the pain and redness,
  • Phototherapy – or light therapy to prevent seasonal episodes of PLME.

Your skin will be exposed to UVA or UVB that can help your skin to be less sensitive to light.

Psoralen is a type of light therapy plus ultraviolet A (PUVA, combines UVA with a medicine called psoralen that will make your skin sensitive to light and some side effects are headache, itching and nausea.

6 Prevention

To prevent your skin for having polymorphous light eruption, follow some of these tips such as:

  • wear protective clothing to cover your skin;
  • avoid going outdoors during 10:00 AM to 4:00 PM because the sunlight is more intense on these hours;
  • use a broad-spectrum sunscreen with an SPF of at least 15 when going out any re apply after every after two hours;
  • wear a hat so that your face and neck will not be fully exposed to sunlight;
  • and use umbrella for cover.

7 Alternative and Homeopathic Remedies

Some of the alternative medicines used for polymorphous light eruption include:

  • Vitamin E – antioxidant for skin protection and can fight allergic reactions and infection and an effective regimen for a healthy skin,
  • Beta carotene – to help maintain healthy skin because of vitamin A,
  • Tea tree oil – antifungal and antiseptic to reduce the redness and inflammation.

8 Lifestyle and Coping

Some of the lifestyle measures that may lessen the symptoms of polymorphous light eruption include:

  • using cold compress by putting it in the affected area;
  • lightly cover the blisters with gauze;
  • avoid the sun between 10:00 AM – 4:00 PM because the sunlight is intense at these hours;
  • wear protective clothing to cover your skin especially the legs and arms and there are clothing designed to provide protection from the sun that has an ultraviolet protection factor (UPF) of 40 to 50;
  • use sunscreen with at least an SPF of 15, reapply after every two hours.

9 Risks and Complications

Some of the factors that can increase your risk to have polymorphous light eruption include:

  • a family history of PLME or genetic risk factor,
  • more common in women than men,
  • the first episode mostly appears during the teenage years or 20s,
  • people with fair skin or living in northern regions will mostly develop this disorder.