Serositis and Lupus

What is it: Serositis and Lupus

Serositis is a serious symptom of lupus that requires prompt treatment.

Systemic lupus erythematosus is an autoimmune disease, which means that its symptoms are tied to the immune system and inflammation. One of the many symptoms of SLE can be serositis. 

Serositis is what happens when inflammation and excess fluid buildup in parts of the body called serous membranes. Serositis occurs in approximately 12% of people with lupus, according to one study, though the number may be higher. 

Serositis is a serious condition, and requires prompt treatment, but it is also very treatable and can relatively easily be sent into remission when caught and taken care of.

What are Serous Membranes?

The serous membranes are a layer of cells inside the body that line and protect the inside of hollow, sealed areas such as the body cavity and the outer areas of the organs. This membrane, about two layers of cells thick, produces a fluid in between those layers that protects the organs and allows them to move smoothly around the body without friction or damage by lubricating them. 

The serous membranes around the organs also assist them in their particular functions: For example, lung serous tissue allows the lungs to better respond to changes in pressure in the body cavity. This is important because our breathing can only happen if the pressure in the body cavity can change, drawing air into the lungs. 

Serous tissue protecting the heart, however, is more about reducing friction on the hard-working organ as it continuously beats, pumping blood through the body. When the serous membrane of the heart is damaged, it becomes inflexible, and the heart is less able to beat correctly. When the inflammation around the stomach, intestines, or other organs in that area are inflamed, these organs can be affected, leading to problems with digestion, fluid retention, appetite, and kidney function. People with lupus are already more prone to getting cardiovascular disease and having kidney problems, which can make serositis a very serious problem.

A common symptom of serositis is effusion. Effusion is the buildup of fluid in the serous membranes. The membrane swells to hold this bubble of fluid. Because space inside the body is limited, this fluid presses against the organs, giving them less space to work and compressing them. This interferes with the function of those organs in many ways. In particular, though, when it happens to the lungs, the fluid takes up space in the lungs and restricts breathing severely.

Because the serous membranes protect the inside of the body and the surfaces of the organs, it has contact with the protective aspects of the immune system. The fluids of the serous tissue have a lot of immune system cells present, and when inflammation is high, there are even more cells. 

How is Serositis Detected?

Usually, you feel it first. Serositis can be painful, and its other symptoms – shortness of breath, nausea, fatigue, swelling, and fever among others – are very noticeable. The fluid buildup from serositis will show up on a chest x-ray, CT-scan, ultrasound, or electrocardiogram. From there, the doctor may remove some of the fluid and analyze it. Usually, they do this if it is in an easily accessible organ, such as when it occurs in the serous tissue around the heart (peritonitis) or the lungs (pleuritis.)

How is Serositis Treated?

Serositis in lupus is treatable, generally clearing up two months after treatment.  It often does come back after going into remission, however, so patients need to be vigilant. Remission is good. Lupus, as well as many of its symptoms, cannot be cured completely, but can be brought down to low or nonexistent levels for years. 

The fluid that builds up has to be drained to make sure that the lungs can inflate and breathe. The tissues that have been damaged by inflammation may need to be removed as the inflamed tissue can ‘scar over’ into rough-textured tissue. This “fibrinous” tissue can cause strain on the organ and on the immune system. Aside from being painful, damaged serous tissue can increase the risk of blood cancers such as leukemia. Otherwise, the medications used for lupus, such as non-steroidal anti-inflammatories (NSAIDs) and corticosteroids  will also treat serositis. Colchicine, a gout medication that reduces swelling, is also used to treat serositis because it stops the fluid buildup. 

Gout, a condition where uric acid builds up in the joints of the body and causes pain swelling, and inflammation. It is different from serositis but the medication still helps.

Belimumab, according to a 2022 study, might be a good treatment for serositis, but it does suppress the immune system, leaving the body vulnerable to infections.

A Lupus Warrior’s Takeaway

Swelling can happen in other tissues of the body, too, including the joints, hands, and feet. This swelling, caused by fluid retention, is often extremely painful or uncomfortable. 

This is different from the condition known as moon face, which is caused by corticosteroid medications that are used to treat lupus. Moon face is caused by metabolism changes that lead to fat being deposited and stored in unusual areas of the body, usually the face, upper body, and abdomen. This type of “swelling” is just a “rounding” and is harmless and usually not physically painful. However, the changes in the face and body can be very damaging to one’s sense of self and mental health.

Serositis is much more serious, however, and requires immediate treatment.