Nasal Provocation Testing in Occupational Rhinitis (NPT)

In a previous study the investigators found that many bakery workers were sensitized to storage mites, and many had rhinitis symptoms. The role of storage mites as an occupational allergen with clinical relevance has been questioned, and the investigators wanted to investigate whether a nasal provocation with a storage mite extract would trigger symptoms and objective signs of rhinitis in bakery workers and a control group.

The investigations include allergy testing with skin prick testing, and measuring of specific Immunoglobulin E (IgE) in sera, answering a questionnaire, and symptom scoring before and after provocations. The participants will be investigated one day with a placebo, and another day with the allergen extract of either Acarus Siro or Lepidoglyphus Destructor. As a measurement of nasal patency we use the nasal peak inspiratory flow meter, but also clinical scoring of nasal secretion and blockage. Indices of inflammation (ECP and alfa-Macroglobulin) will be monitored in nasal lavage.

rhinitis, allergy, occupational, storage mites, nasal lavage, challenge test, ECP, alfa2Macroglobuline

Participants with storage mite sensitization were challenged with placebo extract and storage mite extract in the nose.

The participants were challenged on two occasions, one with placebo extract, and the other with storage mite extract, but in random order, and without the participants knowing when they received allergen or placebo

Provocation in the nose with an allergen extract of a storage mite (A. Siro or L. Destructor) and with placebo allergen extract (physiologic salt water)

Measurements of indices of inflammation in nasal lavage after specific nasal provocation with storage mite allergen

Indices of inflammation (alfa2-macroglobulin, eosinophil cationic protein) in nasal lavage after specific nasal provocation with storage mite allergen (Acarus Siro or Lepidoglyphus Destructor) twice, the second provocation with doubled allergen concentration

Rhinitis symptoms measured by symptoms score and visual analog scale, before and after specific nasal provocation with storage mite allergen (Acarus Siro, Lepidoglyphus Destructor) twice, the second time with doubled concentration of allergen

Reduction in nasal patency measured by peak nasal inspiratory flow meter after specific nasal provocation with storage mite allergen

Reduction in nasal patency measured by peak nasal inspiratory flow meter before and after specific nasal provocation with storage mite allergen (Acarus Siro, Lepidoglyphus Destructor) twice, the second time with doubled concentration of allergen

Objective signs of rhinitis assessed by rhinoscopy after specific nasal provocation with storage mite allergen

Objective signs of rhinitis assessed by anterior rhinoscopy, and notified as a clinical score before and after specific nasal provocation with storage mite allergen (Acarus Siro, Lepidoglyphus Destructor) twice, second time with the doubled allergen concentration

Inclusion Criteria: bakery workers > 18 years sensitized to a storage mite (A.Siro or L. Destructor) Exclusion Criteria: pregnant or breast-feeding infection in upper or lower airways the last month nasal polyposis