People who live in tropical countries, like Indonesia, may rarely hear about solar urticaria. Solar urticaria is an allergy to sunlight which causes the sufferer to not be exposed to direct sunlight. Although solar urticaria is rarely experienced by people who live in tropical countries, that does not mean you have absolutely no risk of this disease. Because, in addition to the climate of residence, there are several factors that can increase a person's risk of being exposed to solar urticaria. Causes of Solar Urticaria The cause of the emergence of solar urticaria is still not known with certainty. However, this condition appears as an allergic reaction to sun exposure. The immune system's response to sunlight is what causes a number of symptoms to appear on the skin. Some factors that can increase a person's risk of developing solar urticaria are: Suffer from certain skin diseases, such as dermatitis. Using perfume, disinfectants, and certain chemicals, while doi...