There are 2 main antibodies: IgE and IgG.
Image source: Wikipedia.com
The histamine molecule can be easily described with an analogy. It is like a structure where a key needs to be bound and be the right fit for activation to occur. They float all around in your body. Histamines fit into receptors and 'unlocks' the effect. What you want is therefore anti-histamines, which are similar to histamines in the first place, but while they fit into receptors, they don't 'unlock'. Hence this will block out the histamines and no effect will occur.
Some anti-histamines make you drowsy, so sometimes companies tend to market them into sleeping aids as well! Smart but tricky if you ask me! Just make sure you are all aware of this.