Scarred lungs

 

When lung tissue is damaged, scarring may occur, and this phenomeon is called pulmonary fibrosis.

MY father was diagnosed with lung fibrosis. I have never heard of this disease before. What is lung fibrosis?

Lung fibrosis is also known as pulmonary fibrosis. It occurs when your lung tissue becomes damaged for some reason, and scarring subsequently takes place.

This thickened scar tissue makes it more difficult for your lungs to expand properly, so you may find it more difficult to breathe. You see, what happens is that the tissue around and between your lung’s air sacs (called alveoli) become hard and thick.

This makes it more difficult for oxygen to pass from the air sac into the bloodstream, and for carbon dioxide to be expelled.

Because it takes time for your lung to build up the fibrous tissue, this disease usually happens in middle-aged or older people. It also occurs far more often in smokers.

What causes lung fibrosis?

Many conditions can cause this, sometimes without you knowing it was there in the first place. Any lung tissue destruction that goes on for a period of time may cause it. Examples include:

Lung infections: pneumonia, tuberculosis.

Chronic medical conditions that inflame the lung tissue (amongst other body tissues) for a long time, e.g. systemic lupus erythematosus (SLE), rheumatoid arthritis, sarcoidosis, scleroderma, etc.

Occupational and environmental hazards: this one involves exposure to certain toxins and pollutants for a long time. These may include silica dust (in sand mining), asbestos fibres (in roofing), grain dust (in farmers who have to store and mill grain) and bird and animal droppings (in people who work in pet stores or keep pets).

Radiotherapy treatment: for people who receive radiation therapy around the lung area for either lung or breast cancer, scarring may develop. Sometimes, this happens months or years after the initial treatment.

Certain medications: chemotherapy drugs like methotrexate and cyclophosphamide used in a variety of cancers, anti-arrhythmic drugs such as amiodarone, anti-hypertensive drugs such as propranolol, and antibiotics such as nitrofurantoin and sulfasalazine.

In a lot of cases, the cause may never be known. This is then referred to as idiopathic pulmonary fibrosis. It is the most common cause of lung fibrosis.

How will I know if I have lung fibrosis?

Sometimes, it is caught during a routine chest X-ray when you go for a medical check-up. Sometimes, you may have symptoms like shortness of breath, coughing and decreased exercise tolerance – meaning that you pant and become tired easily after minimal exertion.

Most people complain of a dry cough at first which doesn’t go away. Then they slowly progress to shortness of breath – at first during exercise, then later even at rest. Most people think that these symptoms are normal, a sign of “getting old”.

These symptoms can actually be attributed to a lot of other lung diseases, and so it’s difficult to make a diagnosis based on symptoms alone. It’s best to go to a doctor if you have any of these symptoms.

If I decide that I can tolerate the symptoms, is it safe for me to live with this lung fibrosis?

Actually no. There may be complications later on. It doesn’t mean you will definitely develop these complications, but you certainly will have a higher risk of developing them.

You may develop something called pulmonary hypertension (high blood pressure of your lung vessels) because your lung arteries become compressed by the fibrous tissue. This is serious because it can lead to right-sided heart failure as your poor heart has to pump so much harder to get the blood through to your lungs.

You are also at higher risk of developing blood clots originating from your lungs. These clots can travel to your legs, for instance, and cause blockage.

Respiratory failure occurs at a very late-stage, when lung fibrosis is so advanced that your oxygen saturation becomes dangerously low. This can lead to death.

Of course, a most feared complication is lung cancer. Adenocarcinoma, a common type of lung cancer, tends to develop from scar tissue.

What can I do to treat my lung fibrosis?

This can be difficult, because once lung scarring has developed, it is permanent and irreversible. The only real cure is a lung transplant. Understandably, this option is not readily available.

Some types of lung fibrosis can respond to anti-inflammatory agents like steroids, which suppress the body’s immune system and retards further scarring.

Steroids alone are usually not enough, so other immuno-suppressive agents can be added – such as azathioprine, cyclophosphamide and methotrexate. The irony is that these agents can cause further scarring!

To prevent blood clots from forming, some patients are put on warfarin for the long-term.

- Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health advice, computers and entertainment. For further information, e-mail starhealth@thestar.com.my.