Frau mit Sonnenbrille sonnt sich


Sun allergy – when sun and skin are enemies

Published on July 09, 2024

The summer vacations are just around the corner and with them long days in the sun. However, not everyone tolerates sunbathing equally well. Clarification is advisable in the case of severe skin rashes.

The sun’s rays are healthy. They supply the body with vitamin D. They also brighten the mood. However, if you overdo it, you will pay the price with sunburn. People with fair skin or red hair are particularly affected. For the upcoming summer vacations, Professor Peter Schmid, Head of the Allergy Ward at the Dermatology Clinic at the University Hospital Zurich, advises: “Wear a hat, use sunscreen and avoid the midday sun between 11 am and 2 pm.”

When the sun’s rays damage the skin

If there is more than just redness, but pimples, blisters or itchy nodules form on the skin, there is probably a hypersensitivity – known in technical jargon as polymorphic light dermatosis. Around 10 to 20 percent of the population are affected.

Sun allergy: a misunderstanding

Colloquially, the condition is often called sun allergy. This is not entirely correct, as sun allergy is a different, relatively rare immune disorder. “It occurs when the immune system overreacts to sunlight, possibly in combination with medication, creams or even sunscreens,” explains Schmid. A sun allergy can be recognized above all by the fact that skin reactions occur after about an hour. In the case of light dermatosis, however, it takes one to two days.

Train your skin for sunbathing

Neither hypersensitivity nor allergy are dangerous. “However, they can severely restrict the quality of life,” says Schmid. In this case, the skin changes should be clarified. Also because the next steps differ depending on the severity and cause of the blisters and spots.

Treatment of light dermatosis and sun allergy

Light dermatosis is treated with anti-inflammatory medication or creams. In the case of sun allergy, anti-allergic tablets (antihistamines) are used in addition to sun protection. Hardly anyone has to give up sunbathing completely. Because if you don’t suffer from a severe allergy, you can train your skin for sunbathing. With UV hardening, the body slowly becomes accustomed to the sun’s rays.

Diagnosis and clarification

According to Schmid, it is useful for the investigations if those affected take a photo on their cell phone in an acute condition. “We can then make a diagnosis on site with the help of tests.” For example, the effect of UV rays on the skin is simulated. So-called photoallergy tests are also carried out exclusively in the light department of the USZ if a sun allergy is suspected. This involves checking whether certain substances or medications in combination with sunlight are responsible for an allergic reaction.

Online skin check: from the comfort of your own home

Send a photo of the affected skin area and fill out the short questionnaire. Within 24 hours on weekdays, you will receive a reliable diagnosis from our experts. Your data will be transmitted to us encrypted and treated confidentially.

To the online consultation

Responsible specialist

Peter Schmid, Prof. Dr. med.

Senior Attending Physician, Department of Dermatology

Tel. +41 44 255 30 79
Specialties: Allergies of all kinds incl. Neurodermatitis and hives , Tropical and travel dermatology, Mastocytosis and histamine-mediated diseases

Responsible Department