what is it called when you are allergic to the sun
Polymorphic light eruption is a fairly common peel rash triggered by exposure to sunlight or artificial ultraviolet (UV) light.
Symptoms of polymorphic lite eruption
An itchy or burning rash appears inside hours, or up to 2 to iii days after exposure to sunlight.
It lasts for upwards to 2 weeks, healing without scarring.
The rash ordinarily appears on the parts of the skin exposed to sunlight, typically the head, neck, breast and artillery.
The face is not always affected.
The rash
The rash can take many different forms (polymorphic):
- you may go crops of 2mm to 5mm raised, pink or ruddy spots, just redness may be harder to come across on brown and blackness skin
- some people go blisters that plow into larger, dry patches – information technology looks a bit similar eczema
- less commonly, the patches look like a target or "bulls-eye" (it looks a bit like erythema multiforme)
Polymorphic light eruption tin exist easily mistaken for heat rash (prickly estrus).
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 tin do in polymorphic light eruption.
Polymorphic light eruption is thought to touch on about 10% to 15% of the UK population.
Sunlight exposure
The rash may be a rare occurrence or may happen every fourth dimension the skin is exposed to sunlight. It ranges from mild to severe.
Sometimes equally piddling as 20 minutes of lord's day exposure is enough to cause the problem, and it tin can even develop through thin clothing or if y'all're sitting most a window.
But for most people with polymorphic low-cal eruption, the rash develops after several hours outside on a sunny 24-hour interval.
If farther 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 peel 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 earlier settling downward by autumn.
Who's afflicted
Polymorphic calorie-free eruption is more common in women than men.
Information technology particularly affects people who take white skin, although it tin besides affect those with brown and blackness skin.
Information technology usually starts betwixt the ages of 20 and 40, although information technology sometimes affects children.
Causes of polymorphic light eruption
Polymorphic light eruption is idea to be caused past UV light altering a substance in the peel, which the immune system reacts to, resulting in the skin condign inflamed.
It's not passed downward through families, but almost i in 5 people with the condition have an affected relative equally it'south a adequately common condition.
It's not infectious, so there'southward no risk of catching polymorphic calorie-free eruption from another person.
Treatments for polymorphic light eruption
In that location'south no cure for polymorphic light eruption, only using sunscreens and conscientious abstention of the sun will help you manage the rash.
Avoid the sun, peculiarly between 11am and 3pm when the sun'south rays are at their strongest, and clothing protective clothing when outdoors (unless your doctor has advised yous to try hardening your skin).
Innovate your skin to sunlight gradually in the spring.
Sunscreen
Y'all may be prescribed sunscreens to help forbid the rash developing.
Utilize a sunscreen that is SPF fifty or to a higher place with a UVA rating of 4 or 5 stars. Apply sunscreen thickly and evenly around fifteen to xxx minutes earlier going out into the sun
Reapply every 2 hours and straight subsequently you've stale yourself off afterward swimming.
Steroid creams and ointments
A GP can prescribe corticosteroid (steroid) foam or ointment that's merely applied when the rash appears.
Yous should use information technology sparingly, equally oftentimes as the GP advises. Do not use information technology when there's no rash.
Desensitisation or UV treatment
Information technology's sometimes possible to increase the resistance of your skin to the sun.
This involves visiting a infirmary dermatology department 3 times a week for iv to half dozen weeks in the bound.
Your skin is gradually exposed to a little more UV calorie-free every visit to try to build up your skin's resistance.
The furnishings of desensitisation are lost in the winter, so y'all'll have to build upwards your resistance again in the spring.
Hardening or toughening
A GP or dermatologist may propose you to try increasing the resistance of your skin at home.
This is known as "hardening" and involves going exterior for brusk periods in the jump to build up your resistance.
You lot might find the fourth dimension is every bit brusk equally a few minutes at showtime, but you may exist able to gradually build upwards to longer times.
You'll have to be conscientious not to overdo information technology but, every bit you lot brainstorm to understand more about how much light triggers your rash, you lot'll be able to gauge how long to stay out.
Like desensitisation, the effects of hardening are lost in the winter, and then you'll have to build upwardly your resistance again in the spring.
Vitamin D
People with polymorphic calorie-free eruption are at greater run a risk of vitamin D deficiency, equally a certain corporeality of dominicus exposure is needed to make your own vitamin D.
A GP tin 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 pare may harden (go more resistant to sunlight) during the summertime, which means more than dominicus tin can be tolerated without your pare reacting.
The rash may fifty-fifty eventually clear up on its own, although this is unusual.
Hardening of the peel does not always happen, and some people with very sensitive peel may even become the rash in the winter.
For these people, it may be a long-term condition to manage with lifestyle changes and creams.
Page terminal reviewed: 28 July 2021
Next review due: 28 July 2024
Source: https://www.nhs.uk/conditions/polymorphic-light-eruption/