What Causes Solar Urticaria And How Can It Be Treated?

What Is Solar Urticaria?

Solar Urticaria (SU) or Solar Hives is an unusual condition which is caused due to the exposure to UV or ultraviolet radiations. It may also be caused due to the exposure to visible light. The hives or urticaria appears on the covered as well as exposed areas of the skin. This can be classified as a part of physical urticaria. Solar urticaria affects only the areas that are exposed to the sun and can occur in the parts which are covered by a thin cloth as well. The hives disappear in several minutes or it might take a few hours as well. The condition may seem quite difficult to manage and can hinder the overall skin texture. The reaction on the skin is sudden and dramatic as well as the duration cannot be determined.

Solar Urticaria

Once solar urticaria is identified, the treatment may involve medication of antihistamines as well as phototherapy– a desensitization treatment. Plasmapheresis and immunosuppressant’s may be used in extreme cases.

Is Solar Urticaria A Serious Condition?

When a large portion of the skin is affected, it may result in loss of fluid which may cause pallor, nausea and lightheadedness. It is advisable to refrain from developing a tensed state of mind by staying away from solar exposure for a few hours.

What Are The Causes Of Solar Urticaria (SU)?

Release of histamine chemical from the mast cells of the human skin causes solar urticaria. The type of sunlight that causes such hives cannot be determined. The appearance of such hives can be quite dramatic, as they will be developed within a few minutes after the skin is exposed to sunlight. However, short wavelength ultraviolet (UVB) or long wavelength ultraviolet (UVA) along with the visible light may cause this urticaria.

How Does Solar Urticaria Present Itself?

Solar urticaria is similar to all other forms of physical urticaria. The urticaria weal may develop on the skin and can make a skin look red or pink. The surrounding areas may become pale as compared to the skin and can last for a few minutes or for a few hours as well. The lesions may subside when the skin is not exposed to sunlight or any other form of light as well. While disappearing, the skin may not have pigmentation as well. This condition may appear when the skin is exposed to sunlight or when the clothing is very thin.

Risk Factors For Solar Urticaria (SU)

Solar urticaria is seen and witnessed all over the globe and it can begin at any age. People who belong to ages from 20 to 40 are the most affected age group.

Signs and Symptoms of Solar Urticaria (SU)

Burning, stinging and itching may be the primary symptoms of solar urticaria. The rash is associated with a variety of symptoms like low blood pressure, vomiting, headache, nausea and breathing difficulties. When this is observed in extremities, one can seek an emergency treatment. The appearance of symptoms may be quite distressing; however, it is not associated with the physical health as the lesions disappear. Following types of lesions may appear and they vary from person to person:

The symptoms often develop on the skin when few parts of the skin are newly exposed to sunlight. The exposed parts of the body like hands and face might not break out when it comes in contact with the sun.

Solar urticaria appears within 30 minutes after the exposure to sunlight and goes away quickly. If the skin is saved from the sunlight exposure, the rashes may disappear within a short amount of time. When the rashes/hives are exposed to a constant amount of sunlight, it may be quite dangerous as it can become chronic and can reoccur periodically.

If the developed rash worsens or persists, it is advisable to contact a physician. In case of associated problems like the development of rash in and around the mouth with a breathing problems then you must approach an emergency doctor. This can be a serious symptom of allergic reaction and it is better to stop it from growing at the earliest.

Tests To Diagnose Solar Urticaria (SU)

The condition is diagnosed on the basis of its appearance on the skin and the duration which it lasts after being exposed to the sun. You can also take a photograph when such rashes appear and show it to the doctor for better evaluation. Photo-testing may also prove to be helpful and this process involves reproduction of rashes by exposing the skin to various light wavelengths. The process is done only when a doctor refers you to a special treatment center. Other tests may also involve biopsy and a blood test in certain cases.

Treatment For Solar Urticaria (SU)

Finding a permanent cure for solar urticaria may be difficult at times, especially when it is caused by the exposure visible light. Necessary measures will have to be taken to protect your skin from exposure to sunlight and a person may require adjusting his or her lifestyle. The eruptions can be prevented by the following ways:

  • Behavioral alterations: Get out of the house and try spending time when the sun intensity is less.
  • Protective Clothing For Solar Urticaria: Other measures involve wearing a tightly woven cloth which have long sleeves and use hat to protect your face from the sunlight. Wear shoes rather than sandals and gloves while driving a vehicle.
  • Sunscreens for Solar Urticaria:As the condition of solar urticaria is caused due to sensitivity of skin when it is exposed to various types of radiations, a sunscreen may help in protecting your from the harmful rays. Sunscreens that have a higher number of SPF may be used to keep your skin safe when heading out in scorching heat. These creams are helpful as they are formulated to cover UVB, UVA and visible light to a certain degree. Below-mentioned are a few examples of sunscreens that will be available at a local drug store:
    • Delph lotion SPF25
    • E45 Sun lotion SPF25
    • AmbreSolaire lotion SPF 60
    • E45 Sun lotion SPF50
    • Delph lotion SPF 30
    • Sunsense Ultra SPF 60
    • Vichy factor 60A. This sunscreen is available in three colors and you may find a color that matches your skin tone.
    • Ultrablock cream SPF30
  • Use window frames that have photo protection to protect yourself from solar urticaria. The car glasses can be made protective by applying a certain film that blocks UVA and UVB radiations. You may need to replace the windows or films every five years as they may lose their tendency to shield from the harmful radiations. Some cars have such glasses installed on their windows while many do not offer such an alternative. Your skin specialist may be able to offer you details about the UV film suppliers.
  • Use of Antihistamines can help in bringing down the symptoms of Solar Urticaria to a considerable level. Such tablets are available in the market and can be an effective in treating the appearance of weal as well. This drug can be taken in combination with any other medication or may be consumed individually on a larger dose for controlling urticaria. Severe flares may be reduced by using various oral steroids.
  • Desensitization: Even after you have taken a constant dose of antihistamine and the problem still persists, the doctor may ask you to get a phototherapy done at the earliest. This involves exposing the skin to cautious and measured intensity of UVA and UVB radiations to your skin.
  • The following specialized treatments are seldom referred:
    • Plasmapheresis – In this technique the plasma cells from the blood is removed by using certain machines and the red blood cells are then induced in the blood stream of the patient. This may help in the removal of a factor that may be circulating in the blood and causing solar urticaria. This factor is however seen in a very small amount of patients and the technique does not always seem to be effective but is still being evaluated.
    • Immunosuppressants like ciclosporin and prednisolone may prove to be effective, but as they have side effects, the doctors may restrict its use as a part of the dosage.

Cure for Solar Urticaria (SU)

In some cases, the symptoms that are associated with solar urticaria leave the body, but in major cases they remain for a long time. If such thing happens, multiple treatments may be prescribed to reduce the appearance of the symptoms.

Also Read:

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:March 13, 2019

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