Hi.. Thanks for the query.. The symptoms of itching in nose and eyes along with watery eyes and swelling and breathing difficulty is pointing towards ALLERGIC RHINITIS.. It can be due to causes like allergic reaction to irritants like pollen, animal danders, dust and mites and at times even certain trees and grasses.. I would suggest you to consult an Emergency room and get evaluated when you get the reaction and a blood test can be done for confirmation.. The tests will help in ruling out the exact cause of the allergen and once you know the cause of the allergic reaction you can avoid exposure to it to prevent allergy attack.. You can also take anti allergics like Levocetrizine, Allegra etc along with steroid nasal sprays to relieve the symptoms.. Do steam inhalations.. You can also be instilled an Immunotherapy that will help in reducing the severity and frequency of allergic attack.. Hope this helps.. Regards.