What is Reactive Airways Dysfunction Syndrome?

Reactive Airway Dysfunction Syndrome or RADS is a condition commonly mistaken for asthma. Persons suffering from RADS complain of difficulty of breathing, with wheezing and coughing. They are wrongly prescribed medications for asthma but become unresponsive to treatment. The downfall with that practice is than when RADS is not properly managed, the symptoms can become chronic.

RADS vs. Asthma

How is RADS different from asthma? Asthma is an obstructive airway disease caused by the activation of cells that secrete mucus in the airways. It is accompanied by the narrowing or airways. The immune system plays a big role in the development of asthma.

RADS, on the other hand, is a non-immunologic. It can develop from single exposure to highly corrosive irritants such as chemicals and even particulate matter. In the event of the 911 attack, a lot of people in the immediate area were diagnosed of RADS, since they inhaled considerate amount of fumes vapor and matter from the crumbling towers. This condition cannot be managed by asthma treatments and require immediate attention.

Common Irritants

It is produced by injury obtained from inhaling corrosive gas, fumes or vapor. These toxic gases are not found in factories alone. Surprisingly, they are always present in our surroundings, but in varying amounts and concentration.

  • Household – These irritants are commonly found in the stuff that we use in our homes such as sealants, spray paint, bleach and some cleaners.
  • Industry – Most industries make use of chemicals for their production. Due to this, RADS is commonly mistaken for occupational asthma. However, RADS occurs from single exposure to high levels of spray paint, welding, metal-coat removers, heated plastic and acids, epoxy, perfumes and pesticides. It is a must that people involved in lines of work that handle these chemicals must be equipped with the proper gear. Also, employers must ensure that the ventilation and exhaust in buildings are adequate to control the effect of the potentially fatal fumes.
  • Chemicals and Others – Exposure to chlorine, sulphur dioxide, ammonia and acetic acid has been noted to cause injuries to the bronchi or upper airways. Locomotive exhaust, fire and smoke inhalation, tear gas and burning paint fumes may also cause injury to the airways.


Since the symptoms of RADS and occupational asthma overlap, the America College of Chest Physician has come up with the following criteria to arrive at a definitive diagnosis:

  • Must have no immediate complaints of previous respiratory ailments
  • Onset of symptoms after a single event or accident
  • Exposure to high concentration of irritants and caustic fumes
  • With cough, wheezing and dyspnea (difficulty of breathing)
  • Presence of obstruction in airways with or without bronchial hypersensitivity


Up to date, there is still no single management for RADS. There are different treatments available, depending on the chemicals inhaled and the extent of injury. For chlorine exposure, sodium bicarbonate nebulization has been shown to improve expiratory volume and quality of life. Bronchodilators and oral corticosteroids started within the first 3 months have produced favorable outcomes. However, in some cases, the said medications aggravated the symptoms. A treatment still undergoing scientific study is the use of high-dose vitamin D. In a case study, 2000 IU/day of vitamin D was given to a patient unresponsive to asthma treatments. The patient noticed improvements in the breathing and has started to rebuild her life. Now, the suggested treatment is 1000 IU/day. However, further tests should still be done to establish its effectiveness.