Irritant-Induced Asthma: Diagnosis And Management

, University of South Florida College of Medicine, Tampa, Fla.

In This Article

Reactive Airways Dysfunction Syndrome


Several salient points regarding RADS should be emphasized. First, RADS results from a high level of inhalation exposure to a toxic substance. Generally, the intensity of the exposure is such that the affected individual seeks immediate medical attention and may need to be hospitalized. The patient is often able to identify the exact time of the day that the illness began.

Second, the asthma-like condition originates with the exposure. Individuals with preexisting asthma (and therefore preexisting bronchial hyperresponsiveness) may develop pronounced symptoms of cough, wheezing, and shortness of breath induced by a nonspecific irritant exposure. This not RADS, but a temporary exacerbation of a preexisting condition.

Third, RADS is associated with persistent symptoms. Usually, those who survive an acute toxic gas, fume, or aerosol exposure recover completely without significant clinical or physiological sequelae, regardless of the severity of the initial clinical manifestations. In patients with RADS, respiratory symptoms and nonspecific bronchial hyperresponsiveness, by definition, persist for at least three months and commonly for years following an exposure. The available clinical, physiologic and histologic evidence strongly suggests that RADS represents the persistent and severe end of the spectrum of irritant responses in the airways.

Finally, once RADS is established, because of the induced nonspecific bronchial hyperresponsiveness, the patient is then subject to bronchospastic responses from many and varied environmental stimuli, including cigarette smoke, cold air, traffic fumes, and common household chemicals, such as hairsprays, perfumes, and bleaches.


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