Antihistamines work better when theyâï¿½ï¿½re already in place when mast cells release histamine.
Since mast cells release many other active chemicals, antihistamines cannot completely block an allergic reaction; they simply diminish it.
By blocking the action of histamine antihistamines prevent or decrease allergic symptoms.
They decrease itching in the skin, nose, eye, and throat.
The sedative properties of antihistamine should not be minimized.