Late-phase allergic reaction in nasal provocation with fungal allergens

Differentiation between asymptomatic sensitization to fungi and clinically relevant allergy is difficult. The aim of this study was to assess the value of nasal provocation with fungal allergens in the diagnosis of allergic rhinitis with special attention to the late phase of monitoring. Eighteen patients with allergic rhinitis and confirmed sensitivity to molds were included in the study. In 16 patients with allergic rhinitis, nasal provocation with fungal allergens was positive. The provocation tests were performed in the asymptomatic period. Stallergenes nasal provocation extracts were used. Extracts were blinded and patients were not informed whether allergen or control solution was tested. The results of both allergen and control solution challenge were compared. Results of the challenge were assessed with symptoms score (after 5 and 30 minutes and 6 and 24 hours), mast cell tryptase level (before and 30 minutes after), and cytological examination of the nasal fluid (before and 6 hours after), and an early and a late-phase of the allergic response was evaluated. Clinical reaction was noted in 16 patients, with significantly marked late phase of the allergic reaction in 14 subjects. The late phase was the only reaction to the challenge in 6 subjects. Tryptase level rose in 2 subjects, whereas significant increase in eosinophils count was observed in 11 patients (Wilcoxon test, p = 0.001). The nasal allergen challenge with fungal allergen seems to be a promising diagnostic method of allergic rhinitis. Late phase of the allergic reaction seems to be an important part of the assessment.