Health condition
Solar urticaria
Solar urticaria is a rare allergy-type reaction to light itself: within minutes of sun exposure the skin itches, stings and wheals, settling within an hour or two of getting out of the light - phototesting confirms it and defines the culprit wavelengths.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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Itch, burning and hives develop within 5-10 minutes of sunlight on exposed (or even thinly covered) skin and fade within one to two hours indoors
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Large-area exposure can cause faintness and, rarely, anaphylaxis-like reactions - a reason for specialist assessment
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Phototesting in a specialist photobiology unit identifies the triggering wavelengths (UVA, UVB and/or visible light)
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Management: high-dose non-sedating antihistamines, broad-spectrum sunscreens including visible-light protection, phototherapy "hardening" and omalizumab for resistant cases
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
In solar urticaria, light converts a molecule in the skin into an allergen that IgE antibodies recognise, and mast cells respond within minutes - which explains both the astonishing speed of the reaction and why visible light through window glass or thin clothing can trigger it in some people. The rapid on-off pattern separates it from polymorphic light eruption, which appears hours after exposure and lasts days.
Diagnosis and treatment routes
Referral to a photodermatology service allows controlled phototesting to confirm the diagnosis, establish the action spectrum and measure the urticarial threshold, all of which shape practical advice. Up-titrated antihistamines are first line; tinted, iron-oxide-containing sunscreens matter when visible light is a trigger, graded phototherapy can induce tolerance before summer, and omalizumab has good evidence in refractory disease. In much of the UK, a routine NHS referral to the relevant specialist clinic can take several months, whereas an initial appointment with a private consultant is typically available within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a dermatologist with access to photodiagnostic testing. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Solar urticaria.
Quick, plain-English answers to what people ask us most.
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Can you explain what solar urticaria is?
Solar urticaria is a medical condition that can affect people differently depending on severity, underlying cause and overall health. A clinician can confirm the diagnosis and explain what it means specifically for you.
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What causes solar urticaria?
Causes vary and can include genetic, environmental, lifestyle and other health-related factors, and in some people no single clear cause is found. Your clinician can help identify anything relevant to your own case.
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What does solar urticaria look like or feel like?
Symptoms vary between individuals and depend on which body systems are affected and how significant the underlying problem is. Keeping track of what you notice, and when, helps your clinician assess it accurately.
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How worried should I be about solar urticaria?
Severity varies from mild and self-limiting to more significant, depending on the underlying cause and how it's managed. A clinical assessment is the best way to understand what it means in your specific situation.
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Is solar urticaria hereditary or genetic?
This depends on the specific condition — some cases have a genetic or familial component, while others are linked more to environmental, lifestyle or other health factors. If you have a relevant family history, it's worth mentioning to your clinician.
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Is there a cure for solar urticaria?
Many cases can be effectively treated or managed, and prevention strategies exist for some causes, though this depends on the specific underlying reason in your case. Your clinician can explain what's realistic for you.
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How is solar urticaria treated?
Treatment is tailored to the underlying cause and severity, and can range from simple lifestyle or self-management measures to medical or specialist intervention.
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What is the long-term outlook for solar urticaria?
This varies depending on the underlying cause, how early it's identified, and how well it responds to treatment — your clinician can give a more specific expectation once assessed.
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When should specialist referral be considered for solar urticaria?
Specialist referral is worth considering if symptoms persist, are getting worse, or aren't responding to initial treatment — your GP can help decide the right pathway and urgency.
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When should I see a doctor about solar urticaria, and how quickly can I be seen privately?
See a doctor if symptoms are persistent, worsening, or affecting your daily life — earlier assessment generally leads to better management. NHS routine referrals for this kind of concern often take 20–45 weeks or longer depending on the area, while a private consultant can typically see you within about 2 weeks, with faster access to scans and specialist opinion.