Measurement of PC20 histamine with the use of two different nebulizers and measurement of FEV1 and PEF

Abstract
Histamine challenge was performed in 19 patients using two nebulizers (PARI and Wright) and FEV1 and PEF were measured to determine PCOT histamine. FEV1 and PEF gave identical PC20 histamine values. The PARI nebulizer gave PC20 histamine values that were 2.5 doubling concentrations lower than the Wright nebulizer. The reproducibility of histamine challenge with the PARI nebulizer1 was studied in 15 patients and the results suggested that the challenge was reproducible within one doubling concentration of histamine.