Eamonn Brady MPSI provides a clinical overview of Sjögren’s syndrome, an under-diagnosed and troublesome eye condition

If a patient is suffering from dry eyes, dry mouth or dry skin and the cause has not been diagnosed, there is a possibility that they are suffering from a condition called Sjögren’s syndrome. It remains undiagnosed in many people. Sjögren’s syndrome is an autoimmune condition in which the body’s white blood cells attack other cells in the body and the cause is unknown. It was first discovered by Swedish ophthalmologist Henrik Sjögren in the 1930s (‘Sjögren’ is pronounced ‘SHOW-gren’).

The main symptoms of Sjögren’s syndrome are dry eyes and dry mouth and enlargement of the parotid glands (salivary gland located in the cheeks just in front of the ears). Dry eyes and mouth occur in 95 per cent of cases. Fatigue and joint and muscle pains are other debilitating features in many who have the condition.

Research has identified many factors (ie, immunological, genetic, hormonal and inflammatory) that may be involved in causing the condition. One theory is that inflammation or abnormality of the body’s glands causes an autoimmune reaction. It is thought to affect 3-to-4 per cent of adults.

It increases with age and usually starts in the 30s and 40s; the average age of onset is the late 40s and it often doesn’t occur until after menopause in many cases. It is rare in childhood and younger adults. It is nine times more common in women than men; the exact reason for this is unknown, but it is suspected to be related to women’s hormones and the fact that women’s immune systems tend to be more active than men’s.

Over half of Sjögren’s syndrome patients have the condition secondary to an accompanying autoimmune or rheumatic condition, such as rheumatoid arthritis or lupus. Because it is mixed-up with other conditions, it is estimated that the average length it takes for diagnosis is 10 years.

Link with other conditions

Sjögren’s syndrome is called primary if it develops in isolation, and secondary if it occurs with other autoimmune or rheumatic conditions like rheumatoid arthritis, systemic lupus erythematosus, fibromyalgia and systemic sclerosis. It is believed that in 60 per cent of cases, Sjögren’s syndrome occurs with or is linked to other inflammatory autoimmune conditions.

Rheumatoid arthritis is a severe inflammatory condition that causes swelling, pain and deformities in the joints; it tends to run in families. Systemic lupus erythematosus (better known as lupus) is nine times more common in women; it can cause inflammation in all organs in the body, leading to fever, joint pain, muscle pain, fatigue and damage to all major organs if not controlled; lupus is rarer in Europe and more common in people of Afro-Caribbean descent.

Fibromyalgia is a chronic pain disorder characterised by extreme tiredness and fatigue. Scleroderma is an inflammatory condition that affects the skin, leading to hard skin and skin lesions; it can go on to damage other organs if not controlled.

Symptoms of Sjögren’s syndrome

For some, the symptoms are no more than a nuisance; for others, they are more severe and have a profound effect on quality of life if not treated adequately. Whilst dry eyes and dry mouth are common features of Sjögren’s syndrome, most people who develop these symptoms do not have the disease; for example, dry eyes and dry mouth affect about 30 per cent of older people and the majority of cases are not due to Sjögren’s syndrome.

Dry mouth and eyes can also be caused by many medicines, such as tricyclic antidepressants, antihistamines, decongestants, beta blockers (for blood pressure and heart conditions), codeine-type painkillers, diuretics, etc. Therefore, before a patient is diagnosed, it must be checked that they are not taking one of these medicines that could be causing the dry eyes and mouth.

Dry eyes lead to itchy eyes, grittiness and soreness and can lead to damage to the cornea if not controlled. Dry mouth may not be immediately obvious, and the person may not complain of dryness, but of an unpleasant taste, insatiable thirst, difficulty eating dry food such as cream crackers, and soreness.

Dry mouth can lead to:

▶ Swallowing problems and dysphagia (the feeling of something getting stuck in the throat on swallowing).
▶ Loss of taste.
▶ Tooth decay and gum disease.
▶ Sore or cracked tongue.
▶ Difficulty talking.
▶ Thrush (fungal infection) in the mouth.

Severe fatigue occurs in about half of people with primary Sjögren’s syndrome and many find this feature of the disease to be the most troublesome. Many with the condition need to sleep more, but many do not feel refreshed upon awakening. The cause of this fatigue is not fully understood, however hypothyroidism, which is frequently linked with Sjögren’s syndrome, may contribute to it.

Dry skin is a common feature of Sjögren’s syndrome; dry skin can lead to itchiness and irritation of the skin or a ‘burning’ of the skin in some cases. Other symptoms of Sjögren’s syndrome include glandular swelling; dryness of the airways (that can lead to dry cough and chest infections); swelling of the parotid (salivary) glands occurs in one-third of cases and can be painful in some cases, swelling of other salivary glands located under the jaw or in the neck area; muscle ache and aching joints (joint ache occurs in one-third of cases); and Raynaud’s phenomenon (coldness in the extremities of the body such as hands and fingers occurs in about 20 per cent of cases of Sjögren’s syndrome).

Sjögren’s syndrome can also cause peripheral neuropathy in about a quarter of cases, which is damage to the nerve endings in the extremities such as fingers and toes; peripheral neuropathy can cause numbness, tingling, itching, pins and needles, etc.

Prognosis is generally good, unless the condition is part of an associated disorder

Treatment

There is no specific cure for Sjögren’s syndrome; the aim of treatment is to control the symptoms. The person must be referred to a rheumatologist for assessment and diagnosis. An ophthalmologist is often involved in the treatment of the eye problems. Blood tests are required to confirm diagnosis. Alcohol and smoking should be avoided, and thorough oral hygiene is essential. Environmental irritants such as smoke, wind, air conditioning, and low humidity may exacerbate eye symptoms. Exercising as much as possible and a healthy balanced diet are important.
To relieve the dry eyes, artificial tears are effective and should be used regularly. They come in drop form and gel form (gel form has a longer-lasting effect, so is especially suitable before going to bed). There are many brands available over the counter from pharmacies; there is no evidence that one brand is any more effective than the next, though preservative-free versions are recommended by some eye specialists to reduce the risk of a preservative causing irritation.

To relieve dry mouth, drinking plenty of fluids helps keep the mouth moist. Artificial saliva comes in the form of mouth gels, mouthwashes and chewing gum; brands available over the counter in pharmacies include brands like BioXtra and Biotene. As well as moisturising, these brands of artificial saliva have enzymes that help stimulate the saliva glands. Another option for dry mouth is pilocarpine tablets; they are licensed for those who have some residual salivary function left.

The dose is 5mg tablets to be taken four times daily, before each meal and at night. Vaginal lubricants may be required. Infections such as vaginal candidiasis (thrush) are more likely. Hydroxychloroquine (Plaquenil) has be shown to useful in some studies to relieve and control joint and muscle pain, relieve fatigue and treat skin symptoms.

Non-steroidal anti-inflammatory drugs such as ibuprofen can help relieve muscle and joint pain but must be used in moderation, as they can cause side-effects like stomach irritation and ulcers, raised blood pressure and kidney problems and must be used in caution with other conditions like asthma, heart disease and kidney disease. Mild corticosteroid cream such as hydrocortisone 1% cream used sparingly and occasionally may give some relief from the dry skin irritations (though regular moisturisation is key to relieve and prevent dry skin).

Treatment of complications

Sjögren’s syndrome may progress to involve organs such as the kidneys, lungs, skin and lymph glands. Stronger anti-inflammatory medication may be required in these situations. These include:
Steroids: Tablets taken orally that reduce inflammation. They are usually limited to when symptoms are particularly bad, as they can cause side-effects if used long-term, ie, prednisolone.
Immunosuppressants: These drugs suppress the abnormal antibody production that causes Sjögren’s syndrome, ie, stops the body attacking itself. Examples include methotrexate, azathioprine, penicillamine and hydroxychloroquine.

They are reserved for more severe cases, as they can have side-effects and are only commenced by specialist rheumatologists. Close monitoring with regular blood tests is required while taking them, as they can cause blood disorders and can affect the immune system. It is recommended that use of immunosuppressive agents is limited to cases where Sjögren’s syndrome is affecting the major organs such as skin, lungs and kidneys.

Hydroxychloroquine (Plaquenil) tends to be used more frequently than other immunosuppressants, but some studies suggest that evidence towards the benefits of hydroxychloroquine is lacking.

Outlook

Prognosis is generally good, unless the condition is part of an associated disorder, such as other inflammatory conditions like rheumatoid arthritis or systemic lupus erythematosus. Sjögren’s syndrome is not usually life-threatening. Sometimes symptoms can disappear for long periods (go into remission). Rarely, it can develop into more serious problems, such as the kidney and lung conditions.

About one-in-100 people with Sjögren’s syndrome develop a form of cancer called lymphoma, most commonly non-Hodgkin’s lymphoma. Patients with Sjögren’s syndrome should pay close attention to any abnormal swelling in glands around the face or neck, under the arms or around the groin area, as this can be a sign of lymphoma.
References on request