How can I stop itchy nose and throat from allergies?

Allergy sx relief. Oral antihistamines like Claritin or zyrtec or Benadryl (diphenhydramine) (latter 2 may cause drowsiness; so caution with driving) will calm down the itching sensation. If more is needed, see doc for prescription steroid nasal spray, which works differently from the antihistamines & will provide added relief. If allergies severe, see allergist for desensitization therapy.