What is the difference between a mast cell stabilizer and an antihistamine?

Question

I know they both stop a reaction caused by histamines, but how do they work differently? I have take several antihistamines (several as in, I'm really running out of options as far as finding something that works), but I haven't taken a mast cell stabilizer. I have very severe hay fever for about 9 months out of the year and have been seeing an allergist who is a pretty good allergist but terrible at communication (you win some, you lose some). I will see him again soon, and I want to know what kinds of medications to ask him about because really I'm very close to having to start wearing an allergy mask, it is that bad. I will be getting shots soon, but even if they work I won't start to see any results for at least a year he said, so I need something different for the mean time. Thanks.

Answer 1

Mast cells produce and secrete histamines which cause an immune response, which in your case is an allergic reaction. This response is triggered by a signalling pathway between the cells of the immune system.

Antihistamines block receptors on the mast cells so that they don't recieve the signal to release histamine.

Mast cell stabilisers work differently. Histamine is produced and stored in membranes called vesicles in the mast cell and in response to the pathway, they fuse with the outer membrane and the histamine is released. This process requires calcium to be present in the cell (the exact mechanisms of membrane fusion in any system are still unclear) and these drugs block the calcium channels which allow the ions to be taken up into the cell. Thus there is insufficient intracellular calcium for the vesicles to fuse with the outer membrane and histamine is not released.

Good luck with finding the right drug. There are a lot of antihistamines available, but from what I've read a mast cell stabiliser could do the trick for you.