Sunburn turned into itchy rash: Polymorphic light eruption – NHS

06.08.202122.07.2023 by alexxlab

Polymorphic light eruption – NHS

Polymorphic light eruption is a fairly common skin rash triggered by exposure to sunlight or artificial ultraviolet (UV) light.

Symptoms of polymorphic light eruption

An itchy or burning rash appears within hours, or up to 2 to 3 days after exposure to sunlight.

It lasts for up to 2 weeks, healing without scarring.

The rash usually appears on the parts of the skin exposed to sunlight, typically the head, neck, chest and arms.

The face is not always affected.

The rash

Credit:

ISM/SCIENCE PHOTO LIBRARY https://www.sciencephoto.com/media/520428/view

The rash can take many different forms (polymorphic):

you may get crops of 2mm to 5mm raised, pink or red spots, but redness may be harder to see on brown and black skin
some people get blisters that turn into larger, dry patches – it looks a bit like eczema
less commonly, the patches look like a target or “bulls-eye” (it looks a bit like erythema multiforme)

Polymorphic light eruption can be easily mistaken for heat rash (prickly heat).

Prickly heat is caused by warm weather or overheating, rather than sunlight or UV light.

The skin in prickly heat does not “harden” or desensitise, as it can do in polymorphic light eruption.

Polymorphic light eruption is thought to affect about 10% to 15% of the UK population.

Sunlight exposure

The rash may be a rare occurrence or may happen every time the skin is exposed to sunlight. It ranges from mild to severe.

Sometimes as little as 20 minutes of sun exposure is enough to cause the problem, and it can even develop through thin clothing or if you’re sitting near a window.

But for most people with polymorphic light eruption, the rash develops after several hours outside on a sunny day.

If further sun is avoided, the rash may settle and disappear without a trace within a couple of weeks.

It may or may not return when skin is re-exposed to sunlight.

If the skin is exposed to more sunlight before the rash has cleared up, it’ll probably get much worse and spread.

For many people with polymorphic skin eruption, the rash appears every spring and remains a problem throughout summer before settling down by autumn.

Who’s affected

Polymorphic light eruption is more common in women than men.

It particularly affects people who have white skin, although it can also affect those with brown and black skin.

It usually starts between the ages of 20 and 40, although it sometimes affects children.

Causes of polymorphic light eruption

Polymorphic light eruption is thought to be caused by UV light altering a substance in the skin, which the immune system reacts to, resulting in the skin becoming inflamed.

It’s not passed down through families, but about 1 in 5 people with the condition have an affected relative as it’s a fairly common condition.

It’s not infectious, so there’s no risk of catching polymorphic light eruption from another person.

Treatments for polymorphic light eruption

There’s no cure for polymorphic light eruption, but using sunscreens and careful avoidance of the sun will help you manage the rash.

Avoid the sun, particularly between 11am and 3pm when the sun’s rays are at their strongest, and wear protective clothing when outdoors (unless your doctor has advised you to try hardening your skin).

Introduce your skin to sunlight gradually in the spring.

Sunscreen

You may be prescribed sunscreens to help prevent the rash developing.

Use a sunscreen that is SPF 50 or above with a UVA rating of 4 or 5 stars. Apply sunscreen thickly and evenly around 15 to 30 minutes before going out into the sun

Reapply every 2 hours and straight after you’ve dried yourself off after swimming.

Steroid creams and ointments

A GP can prescribe corticosteroid (steroid) cream or ointment that’s only applied when the rash appears.

You should apply it sparingly, as often as the GP advises. Do not apply it when there’s no rash.

Desensitisation or UV treatment

It’s sometimes possible to increase the resistance of your skin to the sun.

This involves visiting a hospital dermatology department 3 times a week for 4 to 6 weeks in the spring.

Your skin is gradually exposed to a little more UV light every visit to try to build up your skin’s resistance.

The effects of desensitisation are lost in the winter, so you’ll have to build up your resistance again in the spring.

Hardening or toughening

A GP or dermatologist may advise you to try increasing the resistance of your skin at home.

This is known as “hardening” and involves going outside for short periods in the spring to build up your resistance.

You might find the time is as short as a few minutes at first, but you may be able to gradually build up to longer times.

You’ll have to be careful not to overdo it but, as you begin to understand more about how much light triggers your rash, you’ll be able to judge how long to stay out.

Like desensitisation, the effects of hardening are lost in the winter, so you’ll have to build up your resistance again in the spring.

Vitamin D

People with polymorphic light eruption are at greater risk of vitamin D deficiency, as a certain amount of sun exposure is needed to make your own vitamin D.

A GP can advise whether you need treatment with vitamin D supplements.

Outlook

Many people with polymorphic light eruption find their skin improves over the years.

Your skin may harden (become more resistant to sunlight) during the summer, which means more sun can be tolerated without your skin reacting.

The rash may even eventually clear up on its own, although this is unusual.

Hardening of the skin does not always happen, and some people with very sensitive skin may even get the rash in the winter.

For these people, it may be a long-term condition to manage with lifestyle changes and creams.

Page last reviewed: 28 July 2021
Next review due: 28 July 2024

Poisoning, Allergy, Treatment, Causes, Pictures, and More

Sun Rash: Poisoning, Allergy, Treatment, Causes, Pictures, and More

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Medically reviewed by Stacy Sampson, D. O. — By Jaime Herndon, MS, MPH, MFA — Updated on December 10, 2021

A sun rash can occur due to a genetic condition or the use of a certain medication. The rash may appear as small blisters and cause an itching or burning feeling, among other symptoms.

Sun rash is a type of photodermatosis, where exposure to sunlight causes a reaction on your skin. One common sun rash is called polymorphous light eruption (PMLE), sometimes also called a sun poisoning rash.

PMLE is a red, itchy rash that appears because of exposure to sunlight.

Many people incorrectly refer to PMLE as a sun allergy. In fact, as mentioned, PMLE is a type of photodermatosis. This refers to a sun-related skin disorder. It is one of the most common forms, occurring in around 10 to 20 percent of people.

Other kinds of sun rash can:

have hereditary causes
relate to the use of certain medications
have links to exposure to compounds in certain plants

We explain how to spot sun rash, what causes it, and how to manage symptoms once they develop.

Sun rash typically appears several hours or days after sun exposure. It can develop anywhere on the body that’s exposed to sunlight. Some kinds of sun rash occur on skin that’s usually covered in the fall and winter, such as your chest or arms.

Characteristics of the rash can vary between people depending on skin type, but they can include:

groups of small bumps or blisters
itchy red patches
areas of the skin that feel like they’re burning
raised or rough patches of skin

If a person also has a severe sunburn, they might also feel a fever or headache.

Some people who get sun rash live with a rare photodermatosis called solar urticaria (sun allergy hives). Folks with solar urticaria may feel the following symptoms alongside sun rash:

faintness
breathlessness
headache
other allergy symptoms

These symptoms will usually happen within a few minutes of sun exposure for people with solar urticaria.

Doctors have yet to work out exactly what causes sun rash.

UV radiation from the sun or artificial sources like sunlamps might cause reactions in some people with a sensitivity to this type of light. The resulting immune reaction triggers the rash.

Some risk factors for certain kinds of sun rash can include:

being assigned female at birth
having light skin
living in Northern regions, such as Scandinavia, Central Europe, and the United States
having a family history of sun rash
living in high altitude areas

If you experience a rash after being out in the sun, it’s important to speak with a doctor, such as a dermatologist (if you have access to one). They can rule out other conditions like contact dermatitis or lupus.

Your doctor can also examine the area to see what kind of sun-induced rash it might be. If you’ve never had a sun rash before and suddenly get one, call your doctor.

You should get immediate medical attention if your rash becomes widespread and painful or if you also have a fever. Sometimes, sun rashes can mimic other, more serious ailments, so it’s best to have a medical professional examine you.

Healthcare professionals do not always recommend treatment for sun rash. Most of the time, it can resolve without treatment in a few days. However, this depends on the specific rash and if there’s severe sun poisoning.

The following remedies can help you manage your comfort while the rash is visible:

Apply anti-itching creams. If your rash itches, an over-the-counter (OTC) anti-itch corticosteroid cream like hydrocortisone can be helpful. OTC oral antihistamines can also help.
Try cold compresses or a cool bath. These can also provide itch relief.
Avoid scratching at any blisters. If you have any blisters or if the rash is painful, don’t scratch or pop the blisters. This can lead to infection. You can cover the blisters with gauze to help protect them and take an OTC pain-relieving medication like ibuprofen (Advil, Motrin) or acetaminophen (Tylenol)
Use gentle moisturizers. As your skin starts to heal, you can use gentle moisturizers to relieve itching from dry or irritated skin.

These remedies aren’t effective for everyone. If the treatments don’t have the desired effect, you might need to reach out to a doctor. They can prescribe you a stronger anti-itch cream or oral medication to relieve symptoms.

For people who regularly take medication for another condition, a doctor can let you know if your sun rash is a side effect of the medication.

If your sun rash is due to an allergy, your doctor might prescribe allergy medication or corticosteroids to help address any symptoms you might be having. Sometimes, a physician will prescribe the antimalarial medication hydroxychloroquine, since it’s been shown to address symptoms of certain types of photodermatoses.

There are precautions you can take to minimize your risk of sun rash happening again:

Wear sunscreen. Apply sunscreen with an SPF of at least 30 about a half hour before going out into the sun, and reapply every 2 hours (sooner if you go swimming or are sweating a lot).
Protect your skin with long-sleeve shirts and a wide-brim hat. You might also want to think about wearing specially made clothes that contain sun protective factors.
Avoid the sun between 10 a.m. and 2 p.m., when the sun’s rays are most intense. For extra protection, stay out of the sun until after 4 p.m.
Depending on the type of sun rash, it may be beneficial to gradually expose yourself to more light in the spring. This might help reduce the likelihood of developing a rash. Work with your doctor to be on the safe side.

Sun rash often goes away on its own, but it can recur with exposure to sunlight.

Sun rash typically goes away within a few days, depending on the underlying cause. If your rash recurs despite taking precautions or doesn’t seem to be improving with treatment, call your doctor.

Last medically reviewed on December 10, 2021

How we reviewed this article:

Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

Harris BW, et al. (2021). Solar urticaria.
ncbi.nlm.nih.gov/books/NBK441986/
Lehmann P, et al. (2011). Photodermatoses: Diagnosis and treatment.
ncbi.nlm.nih.gov/pmc/articles/PMC3063367/
Oakley AM, et al. (2021). Polymorphic light eruption.
ncbi.nlm.nih.gov/books/NBK430886/
Sun poisoning dangers: Symptoms, treatment and prevention. (2014).
share.upmc.com/2014/06/dangers-sun-poisoning/

Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

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Dec 10, 2021

Written By

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Medically reviewed by Stacy Sampson, D.O. — By Jaime Herndon, MS, MPH, MFA — Updated on December 10, 2021

Sun allergy: what it looks like and how to treat it

Likbez

Health

June 12

Check if you thought it was a sunburn.

You can listen to a short version of this article.

What is sun allergy?

Sun allergy is a group of diseases in which painful and itchy red spots appear on exposed parts of the body due to ultraviolet radiation. So most often called a polymorphic light rash, because it is very common: it occurs in 10-20% of Caucasians, more often in women.

In addition to it, sun allergy includes:

Solar urticaria. This is a rare severe disease in which a general allergic reaction occurs, up to anaphylactic shock, and the skin becomes covered with red, itchy blisters.
Chronic actinic dermatitis. This is a condition in which, after the sun, dense dry folded areas appear on the body.
Actinic prurigo, or prurigo. This is another rare skin disease. On parts of the body that are often exposed to ultraviolet radiation, swelling occurs, and after it – an itchy rash.
Phototoxic and photoallergic dermatitis. So called rash after taking substances that increase sensitivity to the sun, or contact with them.

In some conditions, the symptoms are visible almost immediately, and in others – after a few hours.

What are the symptoms of sun allergy

Symptoms vary depending on the disease. But even within one disease, the clinical picture is not the same. For example, a polymorphic rash is so called because in some people the elements have a different shape: someone will have spots, someone will have itchy raised nodules.

This is how manifestations of allergy to the sun most often look. Photo: Valsib / Shutterstock

However, all states have common features. Eruptions appear after exposure to the sun on the face, neck, shoulders, forearms and other open areas and are accompanied by:

itching;
pain;
redness;
swelling;
burning sensation;
discharge of a clear or yellowish liquid from the burn.

Why sun allergy occurs

Just as photosynthesis occurs in plants in the light, various substances in the skin can change under the influence of ultraviolet radiation. Sometimes the resulting compounds cause allergies in people.

Someone’s body reacts to its own changed proteins: the immune system does not recognize them and attacks them as strangers. And for someone, the reaction occurs only after taking medications, applying cosmetics, or getting plant juice on the skin. This is due to the fact that some chemicals have a side effect – photosensitivity, that is, they increase a person’s sensitivity to the sun.

There are two types:

Photoallergy. Signs appear only in susceptible people upon repeated exposure to changed substances, when the immune system has already managed to develop protective antibodies.
Phototoxicity. This is when ultraviolet makes substances poisonous, and the reaction of each individual person depends on the amount of these compounds and the characteristics of the skin, and not the sensitivity of the immune system.

Own predisposition

Scientists do not know exactly where it comes from, but they suggest that sensitivity to ultraviolet increases in those who have:

relatives with an allergy to the sun;
fair skin;
skin diseases.

Medications

Medications can cause both phototoxicity and photoallergy. Most often, the reaction occurs when taking:

antibiotics – tetracyclines, fluoroquinolones, sulfonamides;
non-steroidal anti-inflammatory drugs – ibuprofen, ketoprofen, celecoxib;
diuretics – furosemide, hydrochlorothiazide;
retinoids;
sulfonylurea drugs for diabetes;
neuroleptics;
antifungals – griseofulvin, itroconazole;
quinidine.

Contact with cosmetics and household chemicals

Some substances that come into contact with the skin are phototoxic. Paradoxically, even sunscreens can contain phototoxic ingredients. For example, para-aminobenzoic acid, benzophenes, salicylates and cinnamates. Usually there are such substances:

in perfume;
creams;
essential oils such as bergamot;
fragrances;
disinfectants.

Contact with plants

Reaction to plant sap and ultraviolet light is called phytophotodermatitis. This is a phototoxic reaction common to all humans.

The most striking example is Sosnowski’s dill-like hogweed. In cold areas, before the appearance of a strong sun, they take a selfie with him, and in the south they are afraid like fire. Its danger is not in its own toxicity, but in the fact that the juice contains furocoumarins – substances that cause terrible burns in the sun.

There are also furocoumarins in the juice of lime, celery, amma, fig and psoralea. Therefore, it is better that their juice does not get on the skin of a person who is going to sunbathe.

When to see a doctor

Call an ambulance immediately if you have bleeding under the skin or symptoms of anaphylactic shock: loss of consciousness, sticky and pale skin, difficulty breathing.

See a dermatologist if you experience unusual symptoms after exposure to the sun for the first time. The doctor will ask about your condition, possibly conduct additional tests:

phototesting – a small area of the skin is shined with an ultraviolet lamp and the reaction is observed;
blood tests;
biopsy – a doctor cuts out a piece of skin and sends it for examination under a microscope.

This is to distinguish sun allergy from other skin conditions that also increase photosensitivity. For example, from lupus erythematosus or porphyria.

Also be sure to see a dermatologist if you have already consulted a dermatologist about an allergy to the sun, but rashes appeared on areas covered by clothing or rash and itching did not go away after self-treatment.

What you can do yourself if you are allergic to the sun

Often the symptoms go away on their own when you get out of the sun. If this does not happen, you can try to cure a slight exacerbation of photosensitivity at home.

Apply a cold compress or take a cool shower.
Use an anti-itch cream based on steroids or antihistamines.
If needed, take an over-the-counter antihistamine with chloropyramine, clemastine, or cetirizine.

What the doctor will do

He will teach you how to avoid the sun better and prescribe treatment. Depending on the reaction, these can be antipruritics, antihistamines and steroids, and in severe cases, immunosuppressants, substances that suppress the immune system.

How to prevent future exacerbations

Take precautions:

Avoid sun exposure between 10 am and 4 pm because this is the peak time with the highest UV activity.
Use sunscreen with SPF 30 or 50. Remember to reapply every 2 hours and after swimming.
Wear glasses and protective clothing. Some thin or mesh fabrics let UV light through. Therefore, choose those that are labeled SPF 50 or made from dense fabrics.
After a long break, try to gradually increase the time in the sun so that the skin cells have time to adapt to the light. Many people develop symptoms when they are exposed to a lot of ultraviolet light.
Do not wear perfume or essential oils before going to the beach.
Avoid known triggers. If you know that a certain substance increases your sensitivity to the sun, try to use it less in spring and summer.

Photodermatosis: a common sun allergy

Summer sun dermatitis, often referred to as sun allergy, is the most common form of photodermatosis. This disease is caused by increased sensitivity of the skin to ultraviolet radiation and is caused by exposure to sunlight. This phenomenon is not rare today – about 20% of the population worldwide faces photodermatosis. Allergies show up as small red itchy dots. This usually happens after 12 hours. Relapses are often inevitable. Sun allergies can be more severe: more dots, more itching, and more affected areas.

Sun allergies are very common in women between the ages of 15 and 35. It causes discomfort and negatively affects the appearance, is expressed in the appearance of small red spots that cause intense itching and burning. On the face, these spots usually do not appear, but they are on the neck, shoulders, arms and legs. Other symptoms of photodermatosis: peeling of the skin, rashes in the form of papules or folliculitis (pustules), prolonged pigmentation in the affected areas.

Often the symptoms do not appear immediately. Unlike sunburn, photodermatosis can develop only a few hours after returning home (phototoxic reaction), and sometimes even after a few days (photoallergic reaction).

Photodermatosis is caused by ultraviolet rays, especially UVA rays. Their negative impact is increased by deodorants, perfumes, ointments and creams that were applied to sensitive skin before sun exposure. Some substances in perfumes and cosmetics can react with ultraviolet light and cause allergies. This property has, for example, eosin contained in lipstick, and para-aminobenzoic acid, which is part of some sunscreens. Other substances have a similar effect: phenol, retinoids, salicylic, boric and polyunsaturated fatty acids, parsley juice, rose oil, bergamot, musk, St. John’s wort and sandalwood.

It is not uncommon for medications to cause symptoms of sun allergy. In particular: barbiturates, antihistamines, cytostatics, oral contraceptives, hormone replacement therapy drugs, sulfonamides, chlorpromazine, certain cardiovascular drugs, certain antibiotics and certain anti-inflammatory drugs. An increased reaction to ultraviolet light is also manifested in the case of a decrease in the protective function of the skin due to additional exposure to it (for example, peeling, cosmetic manipulations). Often the cause of photodermatosis is a violation of the hepatobiliary and gastrointestinal tract.

And there is only one way to solve this problem – to prevent its occurrence. The ideal solution is to avoid the sun or wear protective clothing. If the sun cannot be avoided:

do not sunbathe between 11.00 – 16.00
do not use perfumes and creams containing alcohol before going to the beach
sunbathe gradually (20-30 minutes per day)
Use a broad spectrum sunscreen with a strong protection factor (against UVA and UVB rays). The first days only on limited areas of the skin. And only after making sure that there is no photodermatosis, when applying these products to certain areas of the skin, use them on all surfaces of the skin.
reapply the cream every two hours
if it was still not possible to avoid negative effects on the skin, and there is no way to consult a doctor, you can remove the acute manifestations of photodermatosis using cold lotions and special after-sun products containing panthenol.