what are causes of hives on the body
Hives frequently occur following an infection or as a result of an allergic reaction such as to medication, insect bites, or food. Psychological stress, cold temperature, or vibration may also be a trigger. In half of cases the cause remains unknown. Risk factors include having conditions such as hay fever or asthma.
Common foods may be the cause, as well as bee or wasp stings, or skin contact with certain fragrances. Acute viral infection is another common cause of acute urticaria (viral exanthem). Less common causes of hives include friction, pressure, temperature extremes, exercise, and sunlight.
Sometimes a breakout of hives has nothing to do with allergies. 1  Other causes include: 2  infections, including colds. 3  exercise. 4  anxiety or stress. 5  exposure to the sun. 6  exposure to cold, such as from diving into a cold pool. 7  contact with chemicals. 8  scratching.