Abstract
Summary: Routine skin tests were performed over a period of two to four years in 36 individuals, who have either a unilateral or bilateral inheritance of hay fever. One individual gave a positive skin reaction without clinical signs of hypersensitiveness, and 5 developed positive skin reactions while under observation and also contracted hay fever. The skin reaction was negative at the onset of hay fever in one case, but became positive the following season. It was less intense the first season of hay fever and became more intense the following season in another case. In the other 3 cases the skin reactions became positive shortly before or during the onset of hay fever and have not varied since. No correlation could be made in these 5 cases between the intensity of the skin reaction and the mucous membrane sensitivity. Pollen extracts were successfully used to test for mucous membrane sensitivity in these 6 cases.