Human nasal allergen provocation for determination of true allergic rhinitis: methods for clinicians.

The nasal provocation test (NPT) could be more extensively used in the diagnosis of allergic rhinitis by practicing physicians. However, the procedure has not been standardized, and has mainly been utilized for scientific purposes in the US. This review illustrates a wide variety of techniques and approaches to dosing and concentration of allergen extracts, and delivery systems. It also outlines the lack of a unified outcomes-evaluation system, including clinical symptom scores and nasal patency measurements, in different countries. NPT is a safe, simple, and useful method when conducted with the consideration of indications and contraindications. Standardized NPT has the potential to become a more frequently used additional clinical test in the diagnosis of allergic rhinitis.