Could seasonal allergy be a risk factor for acute rhinosinusitis in children?

To evaluate the incidence of acute rhinosinusitis in children with grass pollen induced rhinitis during the period of grass pollinosis. Children with nasal symptoms from grass pollen induced rhinitis but without rhinosinusitis symptoms were selected. Their parents were asked to complete a diary during pollen exposure to report nasal symptoms and drugs used daily. When rhinosinusitis was suspected, the confirmatory diagnosis of acute rhinosinusitis was made by fibro-endoscopy. Children without inhalant allergy served as controls. Seventeen out of 242 children (7.0 per cent) had a diagnosis of acute rhinosinusitis, confirmed by fibro-endoscopy, during grass pollination, compared to 3 out of 65 (4.6 per cent) in the control group (p = 0.49). Among allergic children, those with acute rhinosinusitis had symptoms for a greater number of days and/or a higher symptoms score than children without acute rhinosinusitis. Children with grass pollen induced rhinitis during exposure to pollen have an incidence of endoscopically confirmed acute rhinosinusitis comparable to non-allergic children. This suggests that grass pollen induced rhinitis is a negligible risk factor for acute rhinosinusitis.