I keep breaking out in hives what is causing this?

Many Causes: The cause(s) of hives can be many and varied and depends upon the duration of the hives. If one has hives then a thorough evaluation is needed. Alot of times the cause of the hives is not uncovered and we are left with symptomatic treatment.

Depends on duration: Arbitrarily, hives are defined as acute (<6 weeks) or chronic (>6 weeks). Acute hives are usually secondary to a new exposure, such as a change in diet, medication or personal care product. Chronic hives are much more difficult to figure out and the majority end up being idiopathic, although we are now discovering that approximately 40-50% of these cases are autoimmune.