SJOGREN'S IS COMMON
Sjogren's is not rare, just rarely diagnosed.
With Sjogren's, there is a large gap between diagnostic prevalence and actual prevalence.
In the United States, rare diseases are defined as those impacting less than 200,000 people.
Sjogren’s impacts an estimated 3-4 million people in the U.S, 20-40 times more than the cutoff for rare diseases (1). This makes Sjogren's about as common as rheumatoid arthritis (RA), and three times as common as systemic lupus erythematosus (SLE), two closely related diseases.
Despite being a common, SERIOUS, systemic disease, many clinicians remain unfamiliar with Sjogren’s. This contributes to delayed diagnosis, misdiagnosis, and suboptimal care.
There is a large pool of people living with Sjogren’s who remain undiagnosed.
They are often incorrectly labeled as having fibromyalgia, depression, health anxiety (aka hypochondria), functional neurological disorder, or severe menopause.
How common is Sjogren’s?
In the United States, rare diseases are defined as those impacting less than 200,000 people. The best estimate we have, based on the National Arthritis Data Workgroup (NADW), shows that about 1% of the U.S. population has Sjogren’s. That translates to 3-4 million people in the US, 20-40 times more than the cutoff for rare diseases (1,161). While 90% or more of Sjogren's patients are women, men and children are also impacted. Sjogren's is about as common as rheumatoid arthritis (RA), and three times as common as systemic lupus erythematosus (SLE), two closely related diseases. However, unlike RA and SLE, a lack of clinician familiarity with Sjogren's leads to both extreme delays to diagnosis and inadequate medical care.
Sjogren’s impacts an estimated 3-4 million people in the U.S, 20-40 times more than the cutoff for rare diseases (1). Moreover, this estimate is conservative because it does not include Sjogren’s that co-occurs with related diseases such as rheumatoid arthritis (RA) and/or systemic lupus erythematosus (SLE) (sometimes inaccurately called, "secondary Sjogren’s").
Why do some doctors continue to say that Sjogren’s is rare?
Because few clinicians other than rheumatologists receive any formal Sjogren’s education, they tend to assume that Sjogren’s is uncommon and unimportant. Primary care providers look to rheumatologists for clinical guidance about autoimmune rheumatic diseases (AIRDs) such as Sjogren’s. Because many rheumatologists remain disengaged with Sjogren’s, guidance is rarely offered.
Rheumatologists may be confused by the wide range of Sjogren’s prevalence stated in the literature, 0.02% to 4%. However, Sjogren’s is clearly not a rare disease. The realistic 1% prevalence estimate takes into account the large number of undiagnosed and unreported cases (1).
Lower estimates of prevalence are usually based on the number of patients voluntarily reported to Sjogren’s disease registries. These registries enroll only a small fraction of Sjogren’s patients in the target population. They use strict inclusion criteria that usually exclude large subsets such as SSA negative patients and Sjogren’s associated with another AIRD.
Sjogren’s: Under The Radar
If you don’t know to look for Sjogren's, you don’t look for it.
If you don’t look for it you don’t find it.
If you don’t find it, you think it is rare.
If you think it is rare, you're unlikely to look for it.
Who are the missing, undiagnosed, Sjogren’s patients?
1. Patients with classic Sjogren’s features (the largest group)
Because most clinicians do not know that Sjogren’s is common, they often do not consider the diagnosis in patients with typical Sjogren’s features. Classic presenting symptoms include fatigue, brain fog, joint and muscle pain, dryness, and flu-like malaise. Clinicians rarely ask patients with these chronic flu-like symptoms about dryness. Many patients do not mention dryness, not realizing that it could be related to the big picture.
A recent population-based study of Sjogren’s prevalence in Spain found an estimated 50% undiagnosed rate. This study screened the general population by telephone for sicca symptoms or recurrent salivary gland swelling. People with these symptoms were then evaluated by a rheumatologist (141).
The researchers found large numbers of undiagnosed Sjogren’s patients.
Because non-sicca presentations were not included in this study, 50% is likely to be an underestimate of the actual number of undiagnosed patients.
2. Patients with poor access to medical care
In the U.S., health care costs are a major barrier to care. Gender, age, racial, and class bias may also factor in. The lack of clinicians knowledgeable about Sjogren’s is a major problem worldwide.
"I need advice on finding a GP who thinks Sjogren’s is real!"
3. Seronegative (SSA negative) patients
Many patients have been told by a rheumatologist that they cannot have Sjogren’s without testing positive for SSA. This is simply incorrect. Thirty to forty percent of Sjogren's patients test negative for SSA.
4. Patients who do not meet the current Classification Criteria
Classification Criteria are not diagnostic criteria (77). There are no diagnostic criteria for Sjogren’s. Sjogren’s patients who present with prominent systemic features often do not fulfill the Classification Criteria (139) and it may take years of disease progression before they meet these criteria.
Sjogren's Classification Criteria standardize research populations and help distinguish similar diseases from each other. Many rheumatologists rigidly adhere to the Classification Criteria for making a diagnosis. They may be unaware of the limited accuracy of tests and the over-emphasis on sicca features in the Classification Criteria (36, 77). This leaves many Sjogren’s patients undiagnosed.
Sjogren’s is a big picture diagnosis.
An experienced clinician understands the limitations of current diagnostic tests. Diagnosis should never be reduced to a box ticking exercise of the items listed in the Classification Criteria. The entire clinical picture, including symptoms, medical history, family history, physical examination, lab tests, etc. should be taken into account. Sjogren’s is a complex disease. It can look very different in different patients. Diagnosis is ultimately a clinical judgment based on expert opinion. (2) The problem is that there are few experts!
5. Patients with non-sicca presentations
Twenty percent of patients present without obvious sicca, including about half of those with prominent neurological features (32) which are often misdiagnosed as functional disorders.
Organ system involvement or lymphoma may be the first sign of Sjogren’s (2, 3, 97). Men are more likely than women to have lymphoma or lung disease at the time of diagnosis (97,160).
"I had been for advocating for years that my lung problems, which started in childhood, were part of a systemic disease. But no one was listening.
My first rheumatologist said that it couldn’t possibly be Sjogren’s because none of the classic Sjogren’s blood tests came back positive. He reluctantly agreed to send me to a specialist for dry mouth. She suspected Sjogren’s immediately and ordered a lip biopsy which was positive, and eventually moved me to a knowledgeable ophthalmologist who quickly confirmed the Sjogren’s diagnosis.
The onset of my symptoms occurred 32 years before my initial Sjogren’s diagnosis and after that, another two-plus years for a lung diagnosis. I went through 7 lung doctors to find one that finally, correctly, diagnosed my lung problems as Sjogren’s complications."
~ Patient with debilitating Sjogren’s lung disease
6. Patients with predominant sicca manifestations
Sicca-dominant patients are often told for years that they have “sicca syndrome” or “keratoconjunctivitis sicca (KCS)”. An average of 10 years passes from the time a patient is diagnosed with dry eye disease until they are diagnosed with Sjogren’s (35). Sicca patients are rarely asked about systemic symptoms by dentists and eye doctors. Training these clinicians about common systemic features of Sjogren’s and encouraging them to ask their sicca patients about these features could lead to more timely diagnoses.
Thanks to the Sjogren’s Foundation, the new ICD 10 billing codes now emphasize the distinct difference between Sjogren’s and sicca syndrome.
7. Patients misdiagnosed as having another connective tissue disease.
Sjogren’s alone is sometimes mistaken for another disease, frequently RA or SLE (23). This occurs more often in patients with inflammatory arthritis or organ system involvement, simply because of a lack of awareness that these features may also occur in Sjogren’s.
8. Patients with associated Sjogren’s (so called “secondary Sjogren’s”)
Clinicians may fail to formally diagnose Sjogren’s when it occurs with another CTD. These can be considered immune system comorbidities of Sjogren's. About 1/3 to 1/2 of Sjogren’s patients fall into this category (122). The correct term for this situation is “associated Sjogren’s", rather than the problematic term “secondary Sjogren’s". Associated Sjogren's appears to have the same disease manifestations as Sjogren’s alone (so called “primary”) (122, 123).
9. Young Patients
Because diagnosis typically occurs late in the disease, Sjogren’s is often talked about as “a disease of middle-aged women.” This label gives the false impression that younger women, men, and children are not impacted by Sjogren’s. It also underscores the problem that there are no tests available to identify Sjogren’s in its early stages. Many patients recall symptoms that started decades before being diagnosed, sometimes during childhood (115).
"I’ve been dealing with symptoms for over 20 years. My doctors didn’t recognize their significance. I finally got diagnosed when menopause hit and my symptoms became severe."
Clinicians rarely consider a Sjogren’s diagnosis in children or young adults. Younger people with Sjogren’s may present with less advanced disease and fewer areas of involvement. Some have dry eyes but not dry mouth, or vice versa. They may have systemic features without dryness at all. Symptoms tend to build over many years before they get taken seriously.
Sjogren’s tends to be far progressed by the time a patient fulfills the Classification Criteria that doctors often use to diagnose the disease. Almost all Sjogren’s patients see multiple doctors over many years before they are finally diagnosed. Patients frequently initiate the process of diagnosis themselves after researching their symptoms and requesting an evaluation for Sjogren’s. This highlights the problem of inadequate clinician education about Sjogren’s.
"It took me 5 to 6 years and THIRTEEN specialists to get a diagnosis.
A neurologist finally diagnosed me."
Sjogren’s needs to be diagnosed to be treated,
but the challenge does not stop with diagnosis.
Sjogren’s patients live with a high burden of disease. Despite this, some rheumatologists do not routinely offer evaluation, monitoring, and treatment for systemic complications and comorbidities in their Sjogren’s patients. Clinicians often fail to address quality of life issues, especially fatigue and brain fog, the main contributors to loss of function and vitality. Sjogren’s is life-altering for most and devastating to many (98,161).
Living with Sjogren’s is bad enough; having to depend on clinicians who are not up to date or who express dismissive attitudes results in medical neglect and emotional harm.
Patients often find themselves without support from their clinicians, friends, or family because so many Sjogren’s myths and misperceptions persist.
It is hard to live with a serious disease that is not taken seriously.
Improving diagnosis rates will raise Sjogren’s awareness. Sjogren’s is common, serious, and always systemic. It should be treated as such.
Sjogren’s Advocate exists to help Sjogren’s patients
advocate for the basic medical care they need and deserve.