Antihistamines are designed to block the effects of the histamine that your body produces.In turn, they decrease the symptoms of the allergy.Many people find the worst symptom of their eczema is severe itching.Scratching relieves the itch, but also makes the inflammation and the itching worse because it causes more inflammatory substances to be released within the skin.However, if itching is still a problem your doctor may prescribe you an antihistamine.Antihistamines are most commonly used to control the symptoms of allergies such as hay fever.
First-generation antihistamines include diphenhydramine (Benadryl), carbinoxamine (Clistin), clemastine (Tavist), chlorpheniramine (Chlor-Trimeton), and brompheniramine (Dimetane).
Among the most popular over-the-counter (OTC) allergy meds are Zyrtec and Claritin.
These two allergy drugs produce very similar results. Both cetirizine and loratadine are nonsedating antihistamines.
Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil.
Once released, the histamine can react with local or widespread tissues through histamine receptors.