Medically reviewed by Dr. A.M. van Coevorden, dermatologist
Sun allergyItchy bumps at the first sun of the year.
Sun allergy is an oversensitive skin reaction to sunlight, especially UVA radiation. Hours to days after the first strong sun of the year, itchy bumps, patches or small blisters appear on skin that was exposed to the sun. Doctors call this polymorphic light eruption. The rash is harmless and clears within a few days without scarring, but often returns every spring.
What is sun allergy?
Sun allergy is the most common form of light sensitivity: an estimated ten to twenty percent of people experience it at some point, women about twice as often as men. The rash can look different from person to person, hence the name polymorphic: red patches, bumps or small blisters, almost always intensely itchy. The spots sit on sun-exposed skin, such as the neck, chest, forearms and legs; the face often stays clear. In children a variant occurs with bumps on the ears, sometimes called spring ears.
Sun allergy is different from sunburn. With sun allergy, itching dominates; with sunburn, the skin feels painful, hot and red.
How does sun allergy develop?
The symptoms arise because the skin overreacts to ultraviolet light, especially long-wave UVA. Why one person gets it and another doesn't is not precisely known; fair skin and predisposition play a part. The timing is typical: the first sunny days of spring or early summer, when the skin isn't yet used to sun after winter. As the summer progresses, the skin usually adapts to the light and the symptoms ease. Sunlight through glass and sunbeds can also trigger the reaction.
What can you do yourself?
If a reaction occurs, stay out of the sun; the rash then usually clears within a few days by itself. Cooling and a soothing cream ease the itch. Prevention works best by letting the skin adapt to sun gradually in spring, avoiding strong sun between 12 and 3 pm and wearing covering clothing. Apply sunscreen generously to uncovered skin at least fifteen minutes in advance and reapply every two hours.
Choose a sunscreen that protects firmly against UVA as well as UVB: UVA in particular is the main cause of sun allergy.
When to see a dermatologist or doctor?
Have your skin assessed if the rash is severe or doesn't clear after staying out of the sun, if spots also appear on skin that wasn't exposed, or if you feel ill or have a fever. Does the sun allergy return every year and limit your summer? Then a dermatologist can help: with an anti-inflammatory cream or tablets against the itch, and for persistent symptoms with light hardening, in which the skin is gradually accustomed to light under supervision in spring.
Please note
Are you taking medication and does your skin suddenly react strongly to sun? Some medicines make the skin extra sensitive to light. Discuss this with your doctor.
Frequently asked questions
How do I recognise sun allergy?
By itchy red patches, bumps or small blisters that appear hours to days after sun exposure, on skin that was in the sun. Itching dominates; with sunburn the skin feels painful and hot instead.
How long does sun allergy last?
If you stay out of the sun, the rash usually clears within a few days, without scarring. If you keep exposing the skin, the symptoms can persist or worsen.
Does sun allergy come back every year?
Often, especially in spring and early summer. As the season progresses, the skin usually adapts to the light and the symptoms ease. With gradual adaptation and good protection, the symptoms can often be prevented.
Which sunscreen helps with sun allergy?
A cream with at least SPF 30 that protects well against UVA as well as UVB, because UVA in particular causes sun allergy. Apply at least fifteen minutes before going into the sun, generously, and reapply every two hours.
When should you see a dermatologist about sun allergy?
If the rash is severe or doesn't clear after avoiding the sun, if spots also sit on unexposed skin, if you have a fever or feel ill, or if the symptoms return every year and limit your summer. The dermatologist can confirm the diagnosis and tailor the treatment.
Sources and more information
- Behandelrichtlijn Zonneallergie (richtlijnen.nhg.org)
- Zonneallergie / Polymorfe lichteruptie (huidarts.com)