• A new study suggests that some people with multiple sclerosis (MS) may unknowingly have an additional autoimmune disorder known as Sjögren’s syndrome.
• Sjögren’s syndrome commonly leads to dry eyes and a dry mouth.
• Symptoms of MS and Sjögren’s syndrome may overlap, and a doctor may mistake Sjögren’s syndrome for MS.

Multiple sclerosis (MS) is an autoimmune condition that leads to a wide range of symptoms. Some people with MS may notice that their eyes or mouth feel unusually dry. A new study suggests that in some cases, these symptoms may actually be a sign of another autoimmune disorder — Sjögren’s syndrome.

Those with MS who experience dry eyes or a dry mouth may want to ask their doctors about Sjögren’s syndrome.

What Did the New Study Show?

In the study, Brazilian researchers surveyed 202 people diagnosed with MS and asked if they had experienced dry eyes, also called xerophthalmia, or dry mouth, also called xerostomia. They found that 1 out of every 5 people experienced one or both of these symptoms, although in many cases, the researchers thought the symptoms related to medications or comorbidities (co-occuring conditions other than MS).

Researchers further studied the 16 people who had symptoms of dryness that couldn’t be explained by other factors. Of this group, about 19 percent — or three study participants — were diagnosed with Sjögren’s syndrome.

The study authors concluded that some people with MS may also have Sjögren’s syndrome. However, they cautioned that further research was needed in order to better understand the connection, if any, between these two conditions.

What Is Sjögren’s Syndrome?

Sjögren’s syndrome is an autoimmune disease in which the immune system attacks normal tissues within the body. In this condition, the body makes antibodies (immune proteins) that harm certain tissues, including:

• Mucous membranes — Tissues that line certain organs or cavities, such as the nose or mouth
• Exocrine glands — Glands that produce moisture, including the tear ducts, salivary glands (which produce saliva), and sweat glands

The two main symptoms of Sjögren’s syndrome are dry eyes and a dry mouth. People with these symptoms may experience itching, burning, or grit-filled eyes, or have speaking or swallowing difficulties.

Some members of MyMSTeam have described what it’s like to live with Sjögren’s syndrome. “My dry eyes are becoming more intense,” wrote one member. “The itching is much worse than allergies or pink eye … . It is also painful when my tongue sticks to my teeth from lack of saliva.”

Another member commented, “I can’t tell you how many times I’ve pulled the skin on my tongue and cracked it.”

Sjögren’s Syndrome and MS: Similarities and Differences

Both Sjögren’s syndrome and MS are autoimmune diseases caused by a dysfunctional immune system. Researchers have found that the two conditions are also each more likely to affect women — Sjögren’s syndrome is nine times more likely and MS two to three times more likely to develop in women compared to men.

The conditions can also have related symptoms. While Sjögren’s syndrome can cause dry eyes and mouth, MS can lead to vision problems or eye pain as well as swallowing problems. Additionally, both conditions can cause fatigue and numbness or tingling sensations.

On the other hand, these two disorders have their differences. In most cases, the immune system attacks different parts of the body in Sjögren’s syndrome versus MS. This can lead to different sets of common symptoms. Sjögren’s syndrome can also cause joint pain and swelling, coughing, skin rashes, and dry skin. People with MS often experience walking problems, muscle spasms or weakness, and a squeezing sensation (known as the MS hug) around the chest.

Is Sjögren’s Syndrome Linked to MS?

MS may not lead to an increased risk of Sjögren’s syndrome, but the two conditions may be related in other ways.

In the recent Brazilian study, researchers found that 1.49 percent of people with MS had Sjögren’s syndrome. This is similar to rates seen in people without MS — researchers estimate that Sjögren’s syndrome occurs in 0.5 percent to 1 percent of the general population.

However, scientific research suggests that Sjögren’s syndrome is underdiagnosed — many people with the condition have not received a diagnosis and don’t yet know they have it. Additionally, about half of people with Sjögren’s syndrome have another autoimmune disorder, such as MS or rheumatoid arthritis. It’s possible that many people with MS have Sjögren’s syndrome without knowing it.

Sjögren’s syndrome is also sometimes incorrectly diagnosed as MS. About 10 percent to 20 percent of people with this condition have lesions (damage) in the central nervous system (brain and spinal cord). These can lead to some of the same symptoms seen in multiple sclerosis. It’s possible that a small number of people who think they have MS may in fact have Sjögren’s syndrome.

One MyMSTeam member who had been diagnosed with both MS and Sjögren’s syndrome wrote, “I was informed eight months ago I may not have MS due to Sjögren’s imitating MS.” Their doctor recommended further testing to clarify the diagnosis.

Diagnosing Sjögren’s Syndrome

Diagnosing Sjögren’s syndrome can be challenging, taking an average of three years. The main symptoms, dry eyes and dry mouth, can also be caused by many other factors, including:

• Diabetes
• Certain viral infections, such as hepatitis C or HIV
• Certain types of tumors
• Lymphoma
• Autoimmune thyroid disease
• Sarcoidosis
• Amyloidosis
• Chronic fatigue syndrome
• Fibromyalgia
• Radiation treatments

Dry eyes and mouth can also occur as a medication side effect. Antihistamines (allergy medications) or diuretics (water pills) are some drugs known to cause dryness. Additionally, dry eyes can develop due to medications used to treat depression and bladder problems, which are more common in people with MS.

Some MyMSTeam members have debated whether their dry eye symptoms are caused by Sjögren’s syndrome. “I looked up Sjögren’s several years ago because of persistent dry eyes and thirst — but I don’t have it,” wrote one member. “I do have dry eye syndrome, however.”

Talking To Your Doctor

It’s difficult to know for sure whether your dry eyes or dry mouth problems are caused by Sjögren’s syndrome, another condition, or medication. However, it is important to let your doctor know if these symptoms are ongoing or worsening. If you do have Sjögren’s syndrome, receiving proper treatments can relieve symptoms and help prevent complications from developing.

Find Your Team

Are you or a loved one living with multiple sclerosis? Consider joining MyMSTeam. Here, you can share your story, ask questions, and connect with people from around the world who understand life with MS. Your team will know what you’re going through and will be ready to help you improve your quality of life and sense of well-being while living with MS.

Have you been diagnosed with Sjögren’s syndrome in addition to MS? Share your story or thoughts in the comments below or by posting on MyMSTeam.