Urticaria is an outbreak of pale red bumps or welts on the skin that appear suddenly. This condition is also called Hives. The swelling is called angioedema. Allergic reactions, chemicals in certain foods, insect bites and medications can cause Hives. The foods that commonly cause hives are nuts, chocolates, fish, tomatoes and milk. The causes for Sheetapitta are excessive intake of salty and pungent foods, consumption of large amounts of sour gruel, excessive intake of mustard, exposure to cold winds, sleeping during the daytime, climatic changes and insect bites.