Rheumatoid Arthritis Lung Disease
When we say that rheumatoid arthritis is a
systemic disease, we mean that the entire body can be involved. In
addition to swollen and painful joints, people with rheumatoid
arthritis (RA) can also have skin nodules, stomach problems, heart
conditions and other manifestations of the disease. One common site
of RA complication is the respiratory system with the development of
RLD, or rheumatoid lung disease.
To understand how this affects the body, it helps to understand the
anatomy of the lungs and how they work. The airway or trachea leads
from the nose to the bronchi, or smaller air passages, in the two
lungs. These branch into even smaller tubes called bronchioles and
end in tiny sacs called alveoli. It is in the alveoli where the
exchange of oxygen and carbon dioxide actually occurs. The blood
flows through the lungs and eventually back to the body through the
pulmonary artery and vein. Lining the chest walls around the lungs
is a membrane of several layers called the pleura.
If you want to picture all of this, think of an upside down tree.
The windpipe or trachea is the trunk with the bronchi being the big
branches and the bronchioles being twigs. The tiny air sacs of the
alveoli look like leaves at the ends of the twigs. Lung disease can
affect any of these structures.
The most common rheumatoid lung disease is called pleural effusion
and occurs when fluid accumulated between the pleura and the lungs
inside the chest. Some people have these effusions and have no
symptoms but they can cause pain, shortness of breath and even
fevers.
The same rheumatoid nodules that sometimes occur under the skin of
RA patients can also crop up inside the lungs. These may or may not
cause any symptoms in different patients. These can be seen on
x-ray, but sometimes require a biopsy to rule out other causes of
masses in the lungs.
Another common form of RLD is called interstitial lung disease. This
involves the tissues of the lungs and is usually diffuse. Other
problems can be narrowing and inflammation of the air passages
and/or sacs, called bronchiolitis or alveolitis, respectively.
Pneumonitis and Caplan’s syndrome are also seen along with RA.
While three times as many women as men develop RA, men are more
likely to have serious lung involvement. The highest risk for severe
RLD is also seen in smokers and in those people whose RA is poorly
controlled. There is currently no specific treatment for RLD and
symptoms are treated as well as possible. The best way to resolve it
is good control of the RA with the aim of remission.
It is common for rheumatoid arthritis patients to have lung
involvement as a complication. Anywhere from 25% to 75% of RA
patients are estimated to have lung disease as a result, but since
there are not always symptoms at first, the percentages could be
even higher. The best prevention is early diagnosis and effective RA
treatment, as well as avoiding smoking. Just as one can live a good
live with RA, RLD is a condition that can usually be managed with
good medical care.
Resources:
About.com website on arthritis section on rheumatoid lung disease:
arthritis.about.com/
Patient information on rheumatoid lung diseases;
www.uptodate.com/
Lung diseases as a complication of RA:
www.healthcentral.com/
Information about the systemic nature of RA and lung involvement:
arthritisinsight.com/