ALLERGIC RHINITIS TO THUJA POLLEN

Allergy to pollen of Cupressaceae has been linked to pollens of Cupres sus, Juniper and Cryptomeria. The authors report 2 cases of rhinitis a nd conjunctivitis induced by thuja, another member of the Cupressaceae family. Monosensitization to thuja pollen has been identified as the causal agent: (1) of a long-standing springtime rhinitis in 1 patient with negative skin tests and specific IgE titers to the main inhalants (specificity of the prick test and nasal provocation with the thuja e xtract was confirmed by a positive RAST) and (2) in a 2nd patient with out former history of allergy, who consulted for conjunctivitis follow ing acquisition of a dog; the standard battery of skin tests, and Phad iotop(R) were all negative. After controls, only the thuja extract gav e significant skin test response. The level of total IgE was low, and RAST was negative. Sensitization and pollen provocation were produced by the intermediary of the dog, carrying thuja pollens on its fur. The immunoprint and the crossed radioimmunoelectrophoresis revealed commo n antigenicity between cypress and thuja extracts.