You heard me right, your friendly neighbourhood birds, the ones you feed or keep as pets, might be causing a severe lung disease, without you being aware.The disease is called Hypersensitivity Pneumonitis (HP), also called Bird fancier's lung disease. HP can be caused by exposure to more than 300 substances. One of the most common agent is bird dropping and feathers.The disease is more common than you may think. Here I attempt to answer your questions regarding the same.
So lets start in the beginning.
How do pigeons cause the disease?
In a person who is genetically predisposed, HP is a consequence of an immune mediated reaction caused by recurrent exposure to bird feather and droppings.
Who is at risk?
Any person with prolonged and continuous exposure to birds is at risk of developing the disease, such as:
Pigeon/bird feeders,
People who are exposed to bird dropping and feathers at their home/work place
People who work with birds or own many birds
Bird hobbyists and pet store workers
Does everyone who is exposed to birds develop the lung disease?
No, not everyone who is exposed will develop a lung disease. It depends from person to person. Although some research has been carried out, we are still not exactly sure as to why only a minority of those exposed to bird feather and dropping, will develop the disease while others won't.
What are the symptoms?
The symptoms of HP depend on whether the disease is acute or chronic.
In Acute HP symptoms of acute, or sudden and occurs 4-6 hours after exposure to a large quantity of allergen.It may resolve in 12 hours to a few days. Symptoms include:
• Shortness of breath
• Dry cough
• Chest tightness
• Chills
• Fatigue
• Fever
Chronic HP typically occurs after long-term low-level antigen exposure and often causes more subtle symptoms. The symptoms include:
• Shortness of breath, especially with exertion or activity
• Cough
• Fatigue
• Weight loss
In rare cases, chronic HP leads to irreversible, permanent scarring of the lungs. This condition is called pulmonary fibrosis. It may lead to fall of oxygen levels in the body.
As these symptoms are nonspecific and the patient maybe unaware of the exposure, diagnosis may be delayed.
When does one suspect it?
When a person with a history of exposure to birds has the above symptoms, one should suspect HP.
What can be done to diagnose?
There are a few simple tests which can be done to come to diagnosis.
Your doctor diagnoses HP by taking a detailed personal history and performing a physical examination. Your doctor listens to your lungs with a stethoscope. If you have HP, your doctor may hear abnormal lung sounds.
A special device called a pulse oximeter is used to measure the oxygen level in your blood.
Often blood test, Chest Xray and Ct scan of the chest are required.Additional tests like bronchoscopy can help diagnose HP. Patient may need a lung biopsy to confirm the diagnosis.
Is HP contagious?
No, HP is not contagious.
What are the treatment options available?
The first line treatment begins with avoiding any bird allergens that cause the symptoms. If the exposure is continuous you may need to change your place of work/ residence
Medications can help reduce the inflammation in the lungs, but you may need to take them for several months. These medications help prevent your immune system from reacting to allergens you inhale.
In severe cases, supportive therapies to help make breathing easier.These include:
bronchodilators and oxygen to raise oxygen levels in your blood
How can I prevent HP?
The best way to prevent pneumonitis is by avoiding exposure to bird allergens causing lung inflammation. If it is impossible to avoid allergens completely, protective masks or other air filters can reduce your exposure.