Time course of symptoms and nasal airway flow after unilateral nasal allergen challenge. Symptom scores (A) and sneezes (B) and ipsilateral (C) or contralateral (D) nasal airway flow after unilateral nasal allergen challenge are shown. Nasal air flow was evaluated by anterior rhinomanometry. Nasal symptoms and airway flow were evaluated before and at all time-points following allergen challenge. The dashed line represents values obtained after control challenge on a separate day using the same protocol. Values presented are means ± SEM (n = 7; *p < 0.05).