The specific inhalation challenge (SIC) is a diagnosis tool to assess airway responsiveness to "sensitizing" substances as opposed to nonspecific stimuli such as pharmacological agents (i.e. histamine, methacholine), cold air and exercise.
[3] The patient enters a sealed chamber and is exposed to the suspected agent in a controlled, non-work, test environment.
Second, the realistic method may exposed the patient to huge concentrations of particles, resulting in unduly severe asthma attacks.
This test requires the patient to breathe aerosols of the suspected agent (asthmagen) through an oro-facial mask or mouth piece.
These asthmagens are aerosolized using closed-circuit chambers, and the quantities and concentrations administered being minute and extremely stable minimize the risk of exaggerated responses.