Criteria for the Reactive Airways Dysfunction Syndrome (RADS)

Irritant-induced occupational asthma is a term used to describe occupational asthma that occurs from exposure to agents considered to be airway irritants, in the absence of sensitization.

Features of Irritant-Induced Occupational Asthma

Criteria for RADS*

  • History of new-onset asthma
  • Symptom onset related to a single high-level exposure (usually accidental)
  • Onset of symptoms </=24 hr after exposure
  • Exposure to a very high concentration of gas, fume, or spray with known irritant properties
  • Symptoms persistent for >/= 3 mo
  • No previous lower respiratory tract symptoms

Modifications to Criteria for RADS**

  • History of new-onset asthma or recurrence of childhood asthma
  • Symptom onset related to one or more high-level exposures
  • Symptoms can begin >24 hr (in some reports, up to several days) after exposure
  • List of exposures includes highly irritating dust (e.g., after the World Trade Center collapse)
  • Airway hyperresponsiveness or reversible airflow obstruction
  • Previous airway disease associated with smoking or atopy may be difficult to rule out

* The criteria for the reactive airways dysfunction syndrome (RADS) were adapted from Brooks et al.

** Patients were considered to have irritant-induced asthma in some studies with one or more of these modified criteria.

 

 

References:

  1. Tarlo SM, Lemiere C. Occupational asthma. N Engl J Med. 2014 Feb 13;370(7):640-9. [Medline]
  2. Brooks SM, Weiss MA, Bernstein IL. Reactive airways dysfunction syndrome (RADS). Persistent asthma syndrome after high level irritant exposures. Chest. 1985 Sep;88(3):376-84. [Medline]
  3. Tarlo SM, Balmes J, Balkissoon R, Beach J, Beckett W, Bernstein D, Blanc PD, Brooks SM, Cowl CT, Daroowalla F, Harber P, Lemiere C, Liss GM, Pacheco KA, Redlich CA, Rowe B, Heitzer J. Diagnosis and management of work-related asthma: American College Of Chest Physicians Consensus Statement. Chest. 2008 Sep;134(3 Suppl):1S-41S. [Medline]
Created Feb 26, 2014.