Common components in pollen extracts.

In order to evaluate the clinical relevance of testing with various pollen extracts in a multi-center investigation from Denmark, 5,052 patients were skin prick tested with the anamnestically relevant extract from a battery of 48. With the aid of a computer program comparing the extracts, two by two calculations were made over the percentage of patients reacting against allergens present in both extracts. Pollen extracts which frequently produce reaction were divided into three separate groups (tree pollen, grass pollen and herb pollen) within which common allergens were so dominant that it seemed advisable in routine examinations to use one extract and one extract only from each group.