Evaluation of dust and dust mite nasal provocation

The relevance of positive epicutaneous tests to dust mite in patients with perennial rhinitis is often not apparent clinically.

We attempted to assess and compare intranasal challenges with both dust and dust mite allergens in skin test positive patients with perennial symptoms.

Thirteen patients allergic to both dust and dust mite by prick testing were challenged intranasally with each allergen at 2-week intervals. Nasal provocation was performed stepwise to a maximum dose of 2,000 pnu (dust) and 500 pnu (mite). The control group was composed of seven symptomatic patients with negative skin tests.

Control patients were uniformly clinically unresponsive to maximum dose. Allergic patients varied considerably in sensitivity but all reacted clinically to at least the final dose with an early response. There were no obvious late phase reactions. Both dust and mite provoked an early phase increase of eosinophil cationic protein in the nasal secretions of control patients. For allergic patients there were early increases of eosinophil cationic protein, prostaglandin D2 and leukotriene C4. Late phase elevations were not observed.

Dust and mite skin test-positive patients with perennial rhinitis had similar early phase responses to intranasal challenge both clinically and with elevations of inflammatory mediators. Clinically unresponsive control patients did show elevated eosinophil cationic protein levels suggesting a possible nonspecific, non-IgE mediated affect of both dust and mite allergens on the nasal mucosa.