It has been previously demonstrated in nasal challenge studies that there is an increased sensitivity to
allergen following an initial
allergen challenge. A similar feature has been demonstrated following natural
allergen exposure in patients with
seasonal allergic rhinitis. To further explore the characteristics of this "priming" phenomenon and its relationship to other expressions of their allergic airway disease, 28
hay fever patients with strictly seasonal disease were studied. Skin tests with the relevant pollen
allergen and
histamine were performed and the size of the immediate and late phase
allergic reaction was determined. An initial nasal
allergen challenge was followed by a rechallenge of the nose with
allergen 24 h later using a lavage technique. Determinations of
TAME-esterase activity, as a
biochemical marker of the
allergic reaction, were made in the returned lavage fluid. The number of sneezes was counted and nasal symptoms were also assessed using a scoring technique. 19 of 28 patients (67%), displayed an increased responsiveness at rechallenge with similar findings in terms of symptom scores and
TAME-esterase measurements. The increase was statistically significant for the symptoms of
nasal blockage, which increased from 0.7 +/- 0.1 (mean +/- SEM) to 1.1 +/- 0.2 (P less than 0.05), and nasal secretion which rose from 1.1 +/- 0.2 to 1.7 +/- 0.2 (P less than 0.01). A composite nasal symptom score which also took account of the number of sneezes, increased from 2.9 +/- 0.4 to 4.0 +/- 0.3 (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)