An inflammation of the lungs (pneumonitis) or breathing difficulty caused by inhalation of noxious chemicals.

Alternative Names

Chronic chemical pneumonitis; Acute chemical pneumonitis

Causes, incidence, and risk factors

Many household and industrial chemicals are capable of producing both an acute and a chronic form of inflammation in the lung. Acute chemical pneumonitis causes edema ( swelling ) of the lung tissue, the movement of fluid into the air spaces in the lung, and decreased ability to absorb oxygen and get rid of carbon dioxide. In severe cases, death may result from lack of oxygen reaching the tissues ( hypoxia ). Chlorine gas is amongst the most irritating of commonly inhaled substances. Exposure to dangerous levels of chlorine gas may occur at home (during use of cleaning materials such as chlorine bleach), in industrial accidents, or near swimming pools. Inhalation of dangerous substances can occur in many different settings, including factories (especially during smelting, welding, or other metal work), the production or use of solvents or pesticides, fires (house fires, wildfires), and the handling of grain. Chronic chemical pneumonitis can follow low levels of exposure to the lung irritant over extended periods of time. This causes inflammation and may provoke fibrosis (scarring) with decreased oxygen exchange and stiffening of the lung. Unchecked, this condition may ultimately lead to respiratory failure and death.

Signs and tests

Tests used to determine the severity of lung involvement include:

Treatment

Treatment is focused on reducing symptoms. Oxygen therapy may be helpful. Corticosteroids may be given to reduce inflammation.

Expectations (prognosis)

The outcome depends on the chemical agent involved, the severity of exposure, and whether the problem is acute or chronic .

Complications

Respiratory failure and death can occur.

Calling your health care provider

Call your health care provider if you experience breathing difficulty after exposure (or possible exposure) to any sort of inhaled substance.

Prevention

Household chemicals should be used only as directed and always in well-ventilated areas. Work rules regarding breathing masks should be followed and the appropriate breathing mask should be worn. Persons who work near fires should take care to limit exposure to smoke or gases.