Dual Symptomatic and Exudative Nasal Responses are not Characteristics of Perennial Allergic Rhinitis

Abstract

Acute and late phase (dual) symptomatic responses after allergen challenge commonly occur in allergic asthma. The aim of the present study was to explore the occurrence of allergen challenge-induced biphasic responses in patients with chronic perennial allergic rhinitis living in an area with high house dust mite (HDM) exposure. Fifteen patients with perennial rhinitis and evident allergy to HDM participated. Nasal challenges with HDM and sham were performed on separate days in a crossover design. Nasal symptoms, forced expiratory volume in 1 s (FEV1) and orally exhaled nitric oxide were recorded every hour for up to 8 h after each challenge. Alpha2-macroglobulin and eosinophil cationic protein (ECP) were analysed in hourly nasal lavages, and nasal histamine provocations were carried out after 8 h. HDM, but not sham, caused an immediate increase in nasal symptoms which gradually abated over the 8-h period. No reoccurrence of nasal late phase symptoms was seen. HDM, but not sham, induced an early increase in alpha2-macroglobulin and ECP levels: both indices remained elevated for up to 3 h after challenge. HDM challenge evoked hyper-responsiveness to histamine expressed as increased nasal symptoms (p < 0.05; HDM vs sham). No differences in exhaled nitric oxide or FEV1 were demonstrated at any one time point between the HDM- and sham-challenged days. It is concluded that nasal symptomatic and exudative late phase responses may not be a general feature, even in subjects with perennial rhinitis challenged with high, symptom-provoking, doses of HDM allergen.