Sinusitis, an inflammatory disease of the sinus, is one of the most co
mmonly reported diseases in the United States, affecting an estimated
14% of the population. The prevalence of sinusitis is rising. Between
1990 and 1992, persons with sinusitis reported approximately 73 millio
n restricted activity days-an increase from the 50 million restricted
activity days reported between 1986 and 1988. Because critical questio
ns remain unanswered about its cause, pathophysiology, and optimal tre
atment, sinusitis continues to generate significant health care costs
and affects the quality of life of a large segment of the U.S. populat
ion. To identify critical directions for research on sinus disease, th
e American Academy of Allergy, Asthma and Immunology and the American
Academy of Otolaryngology-Head and Neck Surgery Foundation, Inc., conv
ened a meeting in January 1996 in collaboration with the National Inst
itutes of Allergy and infectious Disease. This document summarizes the
proceedings of that meeting and presents what is intended to be the b
ackground for future investigation of the many unanswered questions re
lated to sinusitis.