Variations of pollen and mold concentrations in 1998 during the strong El Niño event of 1997-1998 and their impact on clinical exacerbations of allergic rhinitis, asthma, and sinusitis.

Previous studies of pollen and mold dispersal have not correlated meteorological phenomena with clinical exacerbations of asthma, allergic rhinitis, and sinusitis. We utilized the resources of 11 New England Society of Allergy (NESA) pollen collectors, a certified palynologist, over a dozen weather stations for meteorological data, and 10 emergency rooms to explore the effects of the strong "El Niño" of 1997-1998 on our region during the 1998 pollen season. There was a marked increase in the number of clinical exacerbations of asthma, allergic rhinitis, and sinusitis in April, May, and June of 1998. Several emergency rooms reported a greater increase in visits for sinusitis as compared to asthma. In addition, maximum mold counts occurred two to three months earlier than in 1997. Maximum pollen counts were also higher than in 1997, and occurred two to four weeks earlier for most tree pollen types.