<Tr> <Th> Treatment </Th> <Td> Antihistamines, corticosteroids, leukotriene inhibitors </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> ~ 20% </Td> </Tr> <P> Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps . They may also burn or sting . Often the patches of rash move around . Typically they last a few days and do not leave any long - lasting skin changes . Fewer than 5% of cases last for more than six weeks . The condition frequently recurs . </P> <P> 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 . Diagnosis is typically based on the appearance . Patch testing may be useful to determine the allergy . </P>

The medical term for what is commonly called hives is