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Specific Inhalation Challenge
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. Subjects are exposed to a suspected occupational agent in a controlled way under close supervision in a hospital laboratory. The specific inhalation challenges has been considered as the gold standard in confirming the diagnosis of occupational asthma. Methods One of the steps of SIC is to perform a challenge with the suspected asthmagen. Then, FEV1 is subsequently measured using another device and compared to a baseline. A positive response is usually a decrease in baseline FEV1 of 15 to 20 percent. Realistic method The realistic method was developed in the 1970s. The patient enters a sealed chamber and is exposed to the suspected agent in a controlled, non-work, test environment. The asthmagen can be water-soluble and nebulized. If the agent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupational Asthma
Occupational asthma is new onset asthma or the recurrence of previously quiescent asthma directly caused by exposure to an agent at workplace. It is an occupational lung disease and a type of work-related asthma. Agents that can induce occupational asthma can be grouped into sensitizers and irritants. Sensitizer-induced occupational asthma is an immunologic form of asthma which occurs due to inhalation of specific substances (i.e., high-molecular-weight proteins from plants and animal origins, or low-molecular-weight agents that include chemicals, metals and wood dusts) and occurs after a latency period of several weeks to years. Irritant-induced (occupational) asthma is a non-immunologic form of asthma that results from a single or multiple high dose exposure to irritant products. It is usually develops early after exposure; however, it can also develop insidiously over a few months after a massive exposure to a complex mixture of alkaline dust and combustion products, as shown i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |