hypersensitivity pneumonitis


Hypersensitivity Pneumonitis In Your Home


Hypersensitivity Pneumonitis

Is a lung disease typified by inflamed lungs, caused by an allergic reaction to inhaled dust, molds, fungus or chemicals


What Causes Hypersensitivity Pneumonitis?

There are over 300 known substances that can cause hypersensitivity pneumonitis when inhaled. Some have been named after the source of infection such as:

Farmer’s lung: caused by mold on hay, straw and grain. Commonly seen in farmers and people involved with cattle.

Bird fancier’s lung: (also known as pigeon breeder’s disease), caused by inhaling particles from droppings or feathers from many different bird species.

Humidifier lung: caused by inhaling fungus found in air conditioners, humidifiers and heating systems.

Hot tub lung: caused by inhaling bacteria found in the hot tubs water vapor.


Hypersensitivity Pneumonitis Signs And Symptoms

The walls of the tiny air sacs in the lungs fill with white blood cells causing inflammation, and occasionally the air sacs themselves may also fill with fluid presenting with symptoms that are similar to the flu.

The following may appear around 4 -6 hours after inhaling the dust.

Acute Exposure Signs And Symptoms

  • Dry cough
  • Short of breath
  • Tightness in the chest
  • Rales (abnormal lung sounds)
  • Muscle or joint pain
  • Headache
  • Fever
  • Chills
  • Tiredness – lack of energy

The initial symptoms above may last between 12 hours and several days. If prolonged exposure to the dust occurs during this time you may experience the following symptoms:

Sub Acute Exposure Signs And Symptoms

  • Rales
  • Cough
  • Chronic bronchitis
  • Shortness of breath
  • Anorexia or weight loss

Chronic Exposure Signs And Symptoms

  • Cough
  • Chronic bronchitis
  • Short of breath
  • Anorexia or weight loss
  • Fatigue
  • Pulmonary fibrosis (scarring of the lungs)
  • Clubbing of fingers or toes

If you can remove yourself from the source of infection in the early stages the disease is completely reversible and the acute symptoms will only last a few days. If the disease has progressed to where the lungs have developed scar tissue the hypersensitivity pneumonitis has reached a very serious level.

Scar tissue on the lungs is permanent and can affect your ability to breath normally by causing your lungs to become stiffer and less elastic, inhibiting their ability to process oxygen.

Hypersensitivity pneumonitis can lead to the following potentially fatal complications.


Treating Hypersensitivity Pneumonitis

  • The absolute first thing that you must do is to remove yourself from the source of infection

Your doctor may prescribe some of the following supportive therapies.

  • Oxygen therapy
  • Bronchodilators (medication to relax the muscles in your airway making breathing easier)
  • Prescription opioids, used to control shortness of breath, and/or a chronic cough that is not responding to other treatments.
  • Lung transplant


  • Hypersensitivity pneumonitis is caused by an allergy to specific dusts (allergens)
  • This allergy causes your lungs to become inflamed
  • If you detect hypersensitivity pneumonitis in the early stages and remove yourself from the allergen the disease is completely reversible
  • Later stages of hypersensitivity pneumonitis can cause lung scarring
  • Untreated hypersensitivity pneumonitis can lead to life threatening conditions