What is Sjögren’s syndrome?

Sjögren's syndrome should be considered particularly when severe dry eye is present.

Approximately 99% of people with Sjögren's have dry eyes. The reverse statement, however, is not true: not everyone with dry eye has Sjögren's syndrome.

Who does it affect?

Sjögren's syndrome occurs much more often in women, although it may also appear in men.

It generally manifests from midlife onward. In addition to dry eyes, dry mouth is common.

Age, sex and dryness guide the investigation, but none of them establishes the diagnosis by itself.

Dry eyes

Eye dryness can be very intense.

The patient may experience burning, irritation, a gritty sensation or the need to use artificial tears. Dry eye, however, is extremely common and has many different causes.

Finding dry eyes therefore does not automatically mean that someone has Sjögren's. The severity must be assessed and considered together with the other evidence.

Dry mouth

Dry mouth is another important manifestation.

The person may need to drink fluids constantly or use products that replace or stimulate saliva. Dry eyes and dry mouth together increase suspicion, but still do not confirm the diagnosis by themselves.

It is necessary to determine whether there is a true salivary-gland abnormality and whether other findings support the possibility of Sjögren's.

Enlargement of the salivary glands

Some people may develop enlarged or swollen salivary glands.

This finding adds evidence, but it must be interpreted within the complete clinical picture. Like the other findings, it cannot be analyzed in isolation.

Criteria classify; they do not diagnose

In Sjögren's syndrome, “diagnostic criteria” is also often used for what are actually classification criteria.

Criteria may help organize information or classify patients, particularly for research. They do not replace clinical assessment and should not be used as a mathematical formula that automatically confirms or excludes the disease.

A definitive diagnosis of Sjögren's can be difficult.

How is Sjögren’s syndrome diagnosed?

Diagnosis does not depend on one symptom, antibody or test. It requires integration of the medical history, severity of eye and mouth dryness, examination of the salivary glands and, when appropriate, complementary studies.

Tools that may contribute evidence include antibodies, scintigraphy, salivary-gland ultrasound and biopsy. The value of each finding depends on the person's clinical context.

Diagnosis is detective work

Diagnosing this disease requires working like a detective.

Each piece of evidence carries a different weight:

The intensity of eye dryness.
The presence of dry mouth.
Enlargement of the salivary glands.
Antibodies associated with the disease.
Scintigraphy results.
Ultrasound findings in the glands.
The result of a salivary-gland biopsy.

None of these should be used automatically or out of context. Diagnosis comes from integrating all the information and determining the weight of each finding in that particular person.

Antibodies

Antibodies form part of the investigation, but their interpretation depends on the clinical picture.

A laboratory result should not become the diagnosis by itself. There must first be a well-founded suspicion based on the patient's history, symptoms and examination.

Likewise, the investigation cannot be reduced to deciding whether someone has Sjögren's based only on an antibody.

Salivary-gland scintigraphy

Scintigraphy may provide information about salivary-gland function.

It may show hyperfunction or hypofunction. That result is another piece of the investigation, but it must be related to dryness, examination, antibodies and the other studies.

Ultrasound of the salivary glands

Ultrasound may show inflammatory changes in the salivary glands.

It is another tool that can strengthen suspicion when it agrees with the rest of the picture. Finding inflammation on an imaging study, however, does not replace clinical reasoning or prove by itself that Sjögren's is the cause.

A biopsy does not always provide a definitive answer

A salivary-gland biopsy may show chronic inflammation.

The problem is that chronic inflammation can also occur in other diseases. An abnormal biopsy therefore does not necessarily prove that someone has Sjögren's syndrome.

The result must be analyzed with all the other findings. A biopsy cannot be interpreted as an isolated yes-or-no answer.

Integrate evidence rather than count results

Diagnosing Sjögren's is not a matter of counting how many tests are positive.

A person may have dry eyes and mouth but another explanation for those symptoms. Another person may not initially show every expected finding and yet retain a substantial clinical suspicion.

The physician's task is to assemble the pieces, give each the weight it truly deserves and determine whether together they form a coherent explanation.

The objective is not to apply a label quickly. It is to establish as accurately as possible whether dryness and gland abnormalities truly correspond to Sjögren's syndrome.