Methacholine Challenge Testing: A Novel Method for Measuring PD.

Background: New guidelines for methacholine challenge testing recommend reporting the test outcome as dose rather than concentration. Jet nebulizers have historically been used for methacholine challenge testing, but much of the weight loss, often (incorrectly) referred to as aerosol output, is actually evaporation. The Wright nebulizer is well characterized and still widely used, but its availability is unclear, and it is nondisposable.