Nasal allergen challenge in clinical practice - A real life study

Nasal allergen challenge represents, together with skin tests and specific IgE, one of the basic diagnostic tools used in allergology. The goals of the study were to evaluate types of allergens used, the clinical picture of the challenge, and its safety in our daily clinical practice. In total 136 challenges in 109 patients were analyzed. The study group included 60 women and 49 men, with an average age of 34 years. In 15 patients (13.8% of the study group), apart from allergic rhinitis, bronchial asthma was also diagnosed. Eighty-two patients (75.23%) were challenged with 1, and 27 subjects (24.77%) with 2 allergens. The majority of challenges were performed with house dust mites (58 challenges, 42.6%), followed by Alternaria, mugwort, grasses, birch, hazel, and alder. The clinical picture mimicked the symptoms reported after the natural exposure to the specific allergen. The mean score after the allergen challenge in the group with the positive result was 154.95 points (p < 0.05 vs control solution), and in those with negative challenge 36.67 points. Side effects after the challenge, including itchy throat, cough, dyspnea and facial pruritus, were reported by 21 patients. None of side effects was serious or required any medical intervention. Among evaluated factors only female sex (OR 3.59, 95% CI 1.33-9.68, p = 0.012), but not diagnosis of asthma, 2 challenges per day or the type of allergen used, was associated with a higher risk of adverse events. In conclusions, nasal allergen challenge represents safe and valuable diagnostic tool in our clinical practice.