Allergen-induced nasal hyperreactivity appears unrelated to the size of the nasal and dermal immediate allergic reaction

Publisher Website
Google Scholar
Abstract
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 ariway 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 there turned 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 < 0.05), and nasal secretion which rose from 1.1 .+-. 0.2 to 1.7 .+-. 0.2 (P < 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 < 0.01). The TAME-esterase activity in the recovered lavage fluid following challenge with the same allergen dose increased from 11.7 .+-. 2.4 to 18.7 .+-. 2.8 CPM/103 (P < 0.01). No correlation was found between the increased responsiveness and the size of initial immediate reaction either in the nose or in the skin, or the presence or size of any late phase dermal reaction. There was, however, a correlation between the size of initial allergen response in the nose and skin (r 0.43). As an increased responsiveness to allergen appears to be of clinical significance at natural allergen exposure, further studies of the pathophysiology of this phenomenon are called for.