The hives are caused by a immune response of your body. It is a allergic reaction to the insertion of the needle.

Acupuncture needles sometimes cause small bumps and trigger a itch. Don't scratch or touch the points and the sensation should dissapear gradually. Unless they are severe you shouldn't worry.

From a western medical point of view when you insert a needle you trigger the following pathomechanisms.

- immune response
- vasodilation of the blood vessels
- muscle reflex
- innervation of nerves

In most cases a hive at an acupuncture point is a mild immune response which is a natural part of your bodies healing mechanism.