[1] Univ British Columbia, St Paul Sinus Ctr, Dept Surg, Div Otolaryngol Head & Neck Surg, 2600-1081 Burrard St, Vancouver, BC V6Z 1Y6, Canada
[2] Univ Alberta, Dept Respirol, Edmonton, AB, Canada
[3] Univ Toronto, Dept Med, Toronto, ON, Canada
[4] Univ Toronto, Dept Otolaryngol Head & Neck Surg, Toronto, ON, Canada
[5] Dalhousie Univ, Dept Surg, Div Otolaryngol Head & Neck Surg, Halifax, NS, Canada
[6] Dalhousie Univ, Dept Med, Halifax, NS, Canada
[7] Univ British Columbia, Dept Med, Vancouver, BC, Canada
[8] Queens Univ, Dept Med, Div Allergy & Immunol, Kingston, ON, Canada
[9] Univ Manitoba, Dept Otolaryngol Head & Neck Surg, Winnipeg, MB, Canada
[10] Laval Univ, Dept Med, Quebec City, PQ, Canada
[11] Univ Ottawa, Dept Otolaryngol Head & Neck Surg, Ottawa, ON, Canada
[12] Ottawa Hosp, Ottawa, ON, Canada
[13] Western Univ, Dept Med, Div Clin Immunol & Allergy, London, ON, Canada
[14] McMaster Univ, Dept Med, Div Clin Immunol & Allergy, Hamilton, ON, Canada
[15] Univ British Columbia, Div Resp Med, Vancouver, BC, Canada
[16] Univ Calgary, Dept Med, Calgary, AB, Canada
[17] Univ Montreal, Dept Med, CIUSS Nord ile Montreal, Montreal, PQ, Canada
[18] Lakeridge Hlth, Ajax, ON, Canada
[19] Western Univ, Dept Otolaryngol Head & Neck Surg, London, ON, Canada
[20] Univ Calgary, Div Clin Immunol & Allergy, Calgary, AB, Canada
[21] McMaster Univ, Dept Surg, Div Otolaryngol Head & Neck Surg, Hamilton, ON, Canada
[22] McGill Univ, Dept Otolaryngol Head & Neck Surg, Montreal, PQ, Canada
[23] Univ Alberta, Dept Surg, Div Otolaryngol Head & Neck Surg, Edmonton, AB, Canada
[24] Western Univ, Dept Med, London, ON, Canada
[25] Ctr Hosp Univ Montreal, Div Otolaryngol Head & Neck Surg, Montreal, PQ, Canada