For a better understanding of autoimmune hives you need to understand about autoimmune and hives separately.

Auto immune hives is a skin problem found in patients that develop hives due to an autoimmune trigger, i.e. different antibodies.

Hives (name is urticaria) is a skin disorder and appears as white or red, erupted portions in skin and which are usually itchy in nature. The eruptions can be of various sizes and shapes.

An immune system is a defense system, in the living organisms, of biological structures and processes.  It protects against different disease by identifying and killing the path. Sometimes this immune system can freak out and start damaging the body it is supposed to protect. This process is called autoimmune. Click here for more on autoimmune hives.