Can cake cause hives?

Q: My son ate some cake at a birthday party and then developed hives. What causes hives? Could it have been the cake?
-- Sara

A: Hives -- raised, itchy patches on the skin caused by an allergic reaction - can last for a few hours or a few days. They develop when someone is allergic to something (like foods such as eggs or nuts; bee stings; or medicines) and the body releases a chemical called histamine. Histamine causes blood plasma to leak from small blood vessels under the skin, and hives soon appear.

Although most hives go away on their own, it's always a good idea to see a doctor to help figure out what's causing them.

Call 911 immediately if the hives are accompanied by throat tightness, wheezing, breathing trouble, dizziness, or swelling of the face, lips, or tongue.