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Farmer's lung

​​​​​​​Farmer’s lung is an allergy to moldy crop dust that makes breathing difficult. 

Untreated, it can cause permanent lung damage and death.

It's an allergic reaction to dust from moldy hay, but any moldy crop can also cause the problem.

The allergy develops when you handle a moldy crop, especially in an enclosed environment such as a barn.

Crops stored wet develop bacteria and mold causing spoilage. 

Spoiled hay is extremely dusty and that dust carries the spores causing an allergic reaction.

Anyone exposed to moldy crops is at risk for developing farmer’s lung. 

For example, poultry workers, stable workers, pet store workers and others can develop the condition.

Farmer’s lung symptoms range from very mild to more serious depending on your sensitivity to moldy dust and the amount of mold in your lungs.

Symptoms develop over time and with continued exposure to moldy dust. 

Mild symptoms resemble a cold.

Acute Farmer’s Lung

A more serious and intense attack is acute farmer’s lung.

This condition happens when a person breathes in a large amount of moldy dust. It causes:

  • Fever
  • Chills
  • Difficulty breathing
  • Rapid breathing
  • Rapid heart rate
  • Dry cough

Symptoms can last up to 12 weeks and longer, but may ease after 12 hours. 

Acute farmer’s lung is sometimes confused with pneumonia.

Chronic Farmer’s Lung

After several episodes of acute farmer’s lung, you may develop chronic farmer’s lung.

Symptoms include:

  • Weight loss
  • Low energy
  • Increasing shortness of breath
  • Weakness
  • Chronic cough

The condition can last months or longer and worsen if you're still exposed to moldy dust.

Permanent lung damage is possible with continued exposure.

Diagnosis Of Farmer’s Lung

Your doctor has several tests to help diagnosis farmer’s lung, but it's very important to note any exposure to moldy dust during the examination. 

That information helps your doctor confirm farmer’s lung and assess any damage it has caused.

Treatment of Farmer’s Lung

Your doctor can provide treatment of the symptoms of farmer’s lung, but there's no cure.

The first step is to avoid continue exposure to moldy dust.

Medications and bed rest relieve the symptoms. In some cases, you may need oxygen to help you breathe.

Farmer’s lung means you are hypersensitive to moldy hay dust and will remain so for the rest of your life.

Preventing Farmer’s Lung

The best strategy for preventing farmer’s lung is eliminating or reducing exposure to moldy dust.

This is a challenge for farmers who rely on hay or other crops to feed their animals in the winter.

Strategies that reduce spoilage and the production of mold spores help reduce exposure. 

Here are some other suggestions:

  • Avoid working with moldy hay in a closed environment such as a barn
  • Proper ventilation helps when moldy dust in present in a building
  • Use a professional-grade respirator
  • Storing crops in silage rather than bales is an option
  • Equipment to handle feed can reduce exposure
  • Wet down moldy hay before cleaning a barn or silo
  • Work outside when possible – move moldy bales outside before opening

Be Careful

Farmer’s lung is not common, but it's a dangerous allergic disease. 

Once you become hypersensitive to moldy hay, it stays with you​ the rest of your life.

Be sure to tell your doctor if you’ve been exposed to moldy dust. That information is important to your diagnosis and treatment plan.​

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If this is a medical emergency, call 911.

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