Can a person be allergic to black tea? would symptoms show as feeling like theres dust particles in mouth, eyes, throat and mildly itching skin.

Unlikely: I have yet encountered a true case of allergy to tea leaves. However if there are other flavoring added to the tea, the picture is less clear. An allergic reaction usually occurs within minutes to 2 hrs and usually associated with itching. Regardless of the mechanism, if it bothers you, you need to avoid it ,tough as it may be for someone in the UK like taking away donuts from a cop.