Second generation antihistamines include cetirizine hydrochloride (Zyrtec), loratadine (Claritin, Claratyne), fexofenadine hydrochloride (Allegra, Telfast), and desloratadine (Claramax, Clarinex).
When histamine is released by allergic cells in the nose and eyes, the result is sneezing, runny nose, itchy eyes/nose/throat, nasal congestion, and post-nasal drip.
They are all effective antihistamines that are less sedating and have relatively few side effects.
Second generation antihistamines are less likely to cause impairment of cognitive facilities or performance skills.
Anxiety and agitation with diffuse, deep, odd body sensations:"..bones are on fire", "I feel weird all over", "...a deep pricking, crawling sensation...".
Histamine carries its message to a large number of cells by attaching to a special receptor on the cells' surfaces.