Chronic urticaria treated with soft nasal filters.

A 22-year-old boy having two attacks of urticaria per day for the last 5 years and intermittent attacks of sneezing and rhinorrhoea, and without any clues to the causative agent in spite of a detailed history and follow up, showed almost complete relief on wearing an ordinary cloth mask for 3 days. He was subsequently trained to use the soft nasal filters and obtained almost 80% relief in urticaria and complete relief in rhinitis during the next 1 year. Wearing the mask for 2 days again led to complete relief and further training in the proper use of the filters was helpful.