Can you have a sun allergy?

The solar urticaria it is a rare physical urticaria caused by light. A source of illumination, which can be the natural sun or artificial lamps, causes the appearance of welts or hives and a lot of itching. It can be very disabling, chronic, and difficult to treat.

How affects?

The cause is unknown. It can be caused by different types of light and trigger an immune reaction in the skin. In most patients the wavelengths involved are ultraviolet A and visible light, so it can be triggered just as much by the sun on the beach as an indoor lamp of sufficient power.

It is not possible to predict who it will affect, as its cause is unknown. In general, young women suffer the most.

What symptoms does it cause?

Upon exposure to light, symptoms appear quickly:

• Redness
• Itching and hives or hives on the skin
• pain (sometimes)

Patients explain that the reaction is not it is the same before all types of light nor at different times of the day. It may happen that the areas where the light usually touches, such as the face or hands, do not develop hives, but that the arms, legs or the areas of the skin that are normally more covered.

Logically, the intensity and impact of solar urticaria will be greater in sunny countries like ours, especially when people tend to live outdoors. It may be a very disabling disease, which causes social withdrawal, depression and can even motivate a change of residence to a less sunny region.

By limiting exposure to light so much, patients can become deficient in vitamin D, which is important for maintaining bone calcification.

Can sun allergy tests be done?

It is a disease that, although popularly can be called "sun allergy" not studied by common allergy tests. In fact, it should always be studied by a dermatology service that has special tests called photoluminic tests or "phototest". These tests can determine the wavelength involved in solar urticaria and are essential to guide treatment.

Solar urticaria treatment

Once the type of light that causes it has been determined, treatment includes:

• Antihistamines
• Corticosteroids
• Omalizumab (immunosuppressants such as azathioprine, mycophenolate or cyclosporine may be used)

In tertiary dermatology services, generally in public hospitals, an phototherapy treatment aimed at "hardening" the skin through low and progressive doses of ultraviolet radiation to achieve tolerance to light.

The results of all these treatments are difficult to predict, as it is a rare disease and it is difficult to prove them in clinical trials with a significant number of patients. It generally has a long and chronic course, although it can be self-limited over time. There is no way to predict the evolution or to offer a prognosis.

Remember that insurance has a large team of dermatology specialists.

What you should know:

• It can be caused by different types of light and trigger an immune reaction in the skin.
• It is a rare hive that causes redness, itching and hives or hives on the skin. There may even be pain.
• It is diagnosed with a special test called photoluminal tests or "phototest". It usually has a long and chronic evolution.