Examples are hepatitis, hyperthyroidism, lymphomas, collagen vascular diseases,
and cancers of the rectum, kidneys
and gastrointestinal tract. Chronic infections such as chronic sinusitis can be associated with urticaria.
I feel that you should find out the cause of your chronic urticaria by ruling out the various conditions causing it.Also if these air borne allergens are the cause of urticaria in your case,then pls try avoiding them.
I hope that helps. Please do keep me posted.