What hives?

Urticaria is an edematous mass confined to the skin and mucous membrane. It can be characterized by wheals of varying sizes, accompanied by itching symptoms of varying degrees. Some patients also show vascular edema, which can occur at any age. There are many causes of urticaria, including food allergies, and infections caused by various viruses. Some patients suffer from breathing in pollen, animal fur, dust mites, fungal robes, and other volatile chemicals. Other physical causes include excessive skin friction or stress, and exposure to hot and cold sunlight.