Sarah Schafer, MD
Manifestations vs. Comorbidities
Sjogren's manifestations are caused by complex immune system changes that drive the disease. Comorbidities have many causes, but are not direct manifestations of Sjogren's disease. Clinicians should address both manifestations and comorbidities when caring for Sjogren's patients.
Sjogren’s manifestations are caused by a misbehaving immune system.
Sjogren’s is a systemic autoimmune disease that can impact any part of the body. Direct Sjogren’s manifestations are caused when the immune system attacks various organs and tissues. Damage is common in the salivary and tear glands, connective tissues, nerves, and organs. Sjogren’s is never just a sicca (dryness) disease. Systemic (non-sicca) features can be found in almost every patient who is carefully evaluated.
What is Sjogren’s? Learn more here.
What are comorbidities?
Comorbidities are not Sjogren’s manifestations because they are not caused directly by the Sjogren's disease process. On Sjogren's Advocate, a “comorbidity” refers to a separate disease or condition that occurs at higher rates in people with Sjogren’s. This is what "comorbidities” usually means when you read the medical literature.
Sjogren’s comorbidities may be caused by systemic inflammation, shared biologic pathways, medications, impaired nutrient absorption, and other reasons, some of them unknown. Learn more about General Comorbidities here.
Learn more about Immune Comorbidities here.
Sometimes “comorbidity” refers to the co-occurrence of two diseases in a patient even if those diseases are not associated. This alternate definition of “comorbidities” is not helpful for guiding clinical management of Sjogren’s patients as a group.
Sjogren’s manifestations and comorbidities are both important. Comprehensive Sjogren’s care addresses both direct manifestations and comorbidities. Both have a negative impact on health and mortality. An upcoming page will provide a list of known Sjogren’s manifestations. For now, please refer to the Sjogren’s Is More Than Just Sicca Handout and User Guide, a key self-advocacy tool.
Comorbidities are sometimes confused with manifestations. Occasionally, a journal article or website will confuse systemic (non-sicca) Sjogren’s manifestations with comorbidities. I have seen this happen with interstitial lung disease and lymphoma, two diseases that are clearly caused by the Sjogren's disease process. This inaccurate labeling is a holdover from the original, but incorrect, understanding of Sjogren’s as being limited to sicca.
Some comorbidities occupy a “gray zone”.
A few conditions that were once thought to be Sjogren’s manifestations are now categorized as comorbidities. Examples include autoimmune hepatitis and primary biliary cholangitis. The manifestations vs. comorbidities list is likely to be revised as the understanding of Sjogren’s disease progresses. Some Sjogren’s features are caused by a combination of direct manifestations, comorbidities, and/or unrelated medical conditions. For example, small fiber neuropathy (SFN) is a common neurological manifestation of Sjogren’s. If a Sjogren’s patient also has diabetes (a comorbidity) or a history of taking certain cancer drugs (unrelated), their SFN may have multiple causes. A neurologist will need to sort this out in collaboration with other specialists because treatment choices are usually based on the underlying cause(s) of SFN.
The Takeaway Comprehensive Sjogren’s care requires monitoring and management of a wide range of manifestations and comorbidities. Clinicians who hold the outdated view of Sjogren’s as a nuisance sicca disease tend to overlook systemic manifestations or assume them to be comorbidities. This creates long delays to diagnosis and deprives patients of timely treatment.