Correlation between eosinophilic oesophagitis and aeroallergens.

BACKGROUND: Aeroallergens have been implicated in the pathogenesis of eosinophilic oesophagitis. AIM: To determine whether a seasonal variation exists in the diagnoses of eosinophilic oesophagitis and whether there is a correlation with seasonal pollen count. METHODS: A retrospective review was performed from January 2006 to November 2008 to identify eosinophilic oesophagitis patients. Cases were classified by endoscopic date. Daily pollen counts for grass, trees and weeds were obtained from a certified counting station. Per cent of eosinophilic oesophagitis cases were collated seasonally and compared with mean pollen counts for grass, trees and weeds during the same time period. RESULTS: A total of 127 eosinophilic oesophagitis cases were identified (median age 41, range 19-92 years, 84% men). The highest percentage of cases (33.0%; Binomial P = 0.022) was diagnosed in the spring, while the least percentage (16%; Binomial P = 0.0.010) occurred in the winter. There was a significant association between per cent eosinophilic oesophagitis cases diagnosed seasonally and mean grass pollen count (r(s) = 1.000, P < 0.01), but not with trees (r(s) = 0.400, P = 0.600) or weeds (r(s) = 0.800, P = 0.200). CONCLUSIONS: A seasonal variation was seen in the diagnosis of eosinophilic oesophagitis which correlated with pollen counts. These findings have important implications regarding the pathogenesis of eosinophilic oesophagitis, suggesting a potential role for aeroallergens.

Predominant tree aeroallergens of the Washington, DC area: a six year survey (1989-1994).

OBJECTIVE: A 6-year (1989 to 1994) aerobiologic survey of the Washington DC area was performed to identify predominant area tree pollens, atmospheric concentrations, and peak flowering periods. METHODS: Aeroallergen sampling was conducted using a volumetric rotating-arm impaction Rotorod sampler (Sampling Technologies, Inc, Los Altos Hills, California). RESULTS: The Washington DC pollen calendar may begin as early as January when pollen of the Cupresseacea, Aceracea, Pinaceae, and Betulaceae are observed in small amounts. February through June encompasses the major part of our tree season with considerable overlapping of pollination periods for various trees. The Ulmaceae have two distinct pollinating times with later flowering species of elm pollinating August through October coinciding with ragweed season. April is usually the month with the highest weekly average concentrations. Each year oaks contribute more than 50% of the total tree pollen count followed by pollen of the Pinacea, Cupresseacea, Moracea, and Betuleacea. Times for onset of pollination as well as peak atmospheric concentrations varied from year to year. High production years for some tree aeroallergens are low years for others. CONCLUSION: The Washington DC area is exposed to significant atmospheric concentrations of tree pollen from February through June. Establishing what area tree aeroallergens predominate with respect to their atmospheric concentrations and peak pollinating times is essential for the effective diagnosis and treatment of the tree-allergic patient.