<unk>  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<unk>  can be grouped into sensitizers and irritants. Sensitizer-induced<unk>  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 <unk>  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 can also develop insidiously over a few months after a massive exposure to a complex mixture of alkaline dust and combustion products, as shown in the World Trade Center disaster. Unlike those with sensitizer-induced<unk> , subjects with irritant-induced<unk>  do not develop work-related asthma symptoms after re-exposure to low concentrations of the irritant that initiated the symptoms. Reactive airways dysfunction syndrome (RADS) is a severe form of irritant induced asthma where respiratory symptoms usually develop in the minutes or hours after a single accidental inhalation of a high concentration of irritant gas, aerosol, vapor, or smoke. Another type of work-related asthma is work-exacerbated asthma (WEA) which is asthma worsened by workplace conditions but not caused by it. WEA is present in about a fifth of patients with asthma and a wide variety of conditions at work, including irritant chemicals, dusts, second-hand smoke, common allergens that may be present at work, as well as other "exposures" such as emotional stress, worksite temperature, and physical exertion can exacerbate asthma symptoms in these patients. Both<unk>  and work-exacerbated asthma can be present in an individual. A number of diseases have symptoms that mimic<unk> , such as asthma due to nonoccupational causes, chronic obstructive pulmonary disease (COPD), irritable larynx syndrome, hyperventilation syndrome, hypersensitivity pneumonitis, and bronchiolitis obliterans.
Occupational asthma
Mineral dust airway disease
Occupational lung disease
Brittle asthma
Thunderstorm asthma
Organic dust toxic syndrome
Asthma
Reactive airway disease