ALLERGIC MANIFESTATIONS DUE TO ASH (FRAXI NUS-EXCELSIOR L.) POLLEN INPARIS

Allergic manifestations due to ash pollen were mentioned in the earlie st pollen calendars for Paris established some 30 years ago, and are b eing met increasingly in this city. The pollen is released fairly earl y, usually in March, over a short period of time, and is responsible f or acute allergic manifestations that often include asthma. Cross-reac tions with olive tree pollen are common, probably because the ash tree (and the privet) belong to the Oleaceae family. We performed tests fo r ash pollen allergy in 140 patients with rhinitis or asthma in late w inter or early spring. Thirty-six patients had a positive skin test, 1 1 a positive RAST, and 19 (of 41) a positive nasal provocation test at concentrations in the 1/1600-1/200 range. In 23 patients, evaluations done during the ash pollen seasons of the following years established a link between the clinical manifestations and the release of ash pol len. Although standardized ash pollen extracts are not yet available, the skin test and specific nasal provocation test bad a better predict ive value than the RAST, whose sensitivity was low (0.44). However, ol ive tree pollen can be used instead of ash tree pollen for the RAST. A sh tree pollen should be added to the list of potential causes of alle rgic manifestations occurring early in the pollen season in residents of Paris; The development of standardized ash tree extracts would allo w to improve the diagnosis and the use of specific immunotherapy.