Individuals who have physical urticaria have a physical trigger for hives such as heat, pressure, cold, water, sunlight or exercise. Some individuals who have chronic urticaria usually have a physical cause.
Close look on solar urticaria
When it comes to solar urticaria, it is basically a form of chronic hives due to exposure to sunlight. Individuals who have this condition suffer from redness, itching and hives on parts of the body that was exposed to sunlight. At certain times, the symptoms can be confused with sunburn, although solar urticaria can develop within minutes of sun exposure and vanishes after exposure is stopped.
The presence of hives is similar with other forms of urticaria, although the hives only manifest on skin that was exposed to direct sunlight. Hives can also develop even under clothing. Take note that skin that has been exposed frequently to sunlight is not likely to develop hives than skin that was less frequently exposed to the sun.
It simply shows that individuals with solar urticaria produce allergic antibodies against different proteins present in the skin. The structure of these proteins changes with sunlight, thus enabling an allergic reaction to occur that results to hives. It is also possible for an individual with the condition to suffer from anaphylaxis if enough skin was exposed to sunlight.
Diagnosis
Solar urticaria could not be diagnosed based on the history of symptoms alone since other conditions such as polymorphous light eruption and some forms of porphyria can also trigger rashes once exposed.
A diagnosis is made once the skin is exposed to different forms of light that can generate various spectrums or wavelengths. This is a special test that is often performed by dermatologists. Oftentimes, a diagnosis is made after being exposed to natural sunlight.
Treatment of solar urticaria
The symptoms can be reduced by using various antihistamines as well as applying topical steroid creams such as hydrocortisone. In some circumstances, oral steroids such as prednisone are needed to manage severe symptoms.
It is also possible to desensitize the skin with repeated exposure to sunlight so that hives will not develop in the future. This special form of therapy should be performed by a dermatologist usually for a few days and should be repeated frequently.