Wheals can develop anywhere on the body, mostly in the sun exposed skin. The action spectrum of solar urticaria is broad, ranging from UVC, UVB, UVA to visible spectrum. Avoidance of sunlight is important. The body should be covered with clothing and the patient should be advised to use an appropriate sunscreen. Antihistamines can give symptomatic relief and may be helpful as a preventive measure if taken before sun exposure.
Characteristic urticaria appears on exposed areas on a cold day.
Handling of cold objects causes immediate local reaction. Swelling of the mouth and oesophagus may occur on drinking cold water. Extensive cold urticaria may be associated with systemic symptoms such as faintness, wheezing and palpitations. Syncope can occur when the patient immerses in cold water. Wheals form on rewarming.