Sjögren’s and Lupus: What Patients Should Know

Overlapping Symptoms and How Doctors Differentiate Them

Living with an autoimmune disease can be challenging—and when symptoms of more than one condition appear, it might feel overwhelming. Two of the most frequently discussed autoimmune diseases are systemic lupus erythematosus (lupus) and Sjögren’s syndrome. Although they share certain clinical features and may even coexist in one patient, each condition has unique characteristics. Understanding both the commonalities and the differences can empower patients to work more effectively with their healthcare providers.

Understanding Lupus

Systemic lupus erythematosus (SLE) is a chronic autoimmune condition in which the immune system mistakenly attacks healthy tissues. Key points about lupus include:

• Multisystem Involvement: Lupus can affect the skin, joints, kidneys, heart, lungs, and nervous system.
• Classic Symptoms: Many patients notice a distinctive “butterfly” rash across the cheeks and nose, alongside photosensitivity (an unusual reaction to sunlight), joint pain, and fatigue.
• Lab Markers: Lupus is often associated with a positive antinuclear antibody (ANA) test, elevated anti-double stranded DNA (anti-dsDNA) antibodies, and other autoantibodies.
• Disease Course: Lupus is characterized by periods of flares (increased disease activity) and remission, meaning symptoms may worsen and then improve over time.

Because of its complex nature, lupus can vary widely from one person to the next. Some individuals experience mild symptoms, while others face more severe, potentially life-threatening complications such as kidney inflammation (lupus nephritis).

Understanding Sjögren’s Syndrome

Sjögren’s syndrome is also an autoimmune disease—but its hallmark is the attack on the body’s moisture-producing glands. Here’s what you need to know:

• Primary Features: The most common symptoms include persistent dryness of the eyes (keratoconjunctivitis sicca) and mouth (xerostomia). This dryness can extend to other areas such as the throat, skin, and even the vagina.
• Beyond Dryness: While dryness is the central feature, Sjögren’s can also lead to joint pain, fatigue, and in some cases, affect other organs.
• Diagnostic Markers: Patients with Sjögren’s often have specific autoantibodies such as anti-Ro/SSA and anti-La/SSB. In addition, objective tests like the Schirmer’s test (to measure tear production) and salivary flow rate measurements are used.
• Primary vs. Secondary: Sjögren’s can occur alone (primary) or alongside another autoimmune disease—often lupus or rheumatoid arthritis (secondary).

Because Sjögren’s primarily impacts the glands, its symptoms are usually more focused on dryness. However, extraglandular features (those beyond the glands) can occur and sometimes overlap with symptoms seen in lupus.

Overlapping Symptoms: Where the Lines Blur

Both lupus and Sjögren’s syndrome share several overlapping features, which can sometimes make it difficult to tease the two apart. Common overlapping symptoms include:

• Fatigue: Both conditions can cause profound tiredness that affects daily life.
• Joint Pain and Stiffness: Arthralgia is common in lupus and can also be seen in Sjögren’s.
• Autoantibodies: Many patients with either condition have positive ANA tests. In fact, anti-Ro/SSA antibodies can be found in both, although they are more classically associated with Sjögren’s.
• Systemic Inflammation: Even when internal organs are not heavily involved, systemic inflammation can be present in both diseases.

For patients, these similarities can sometimes result in a “diagnostic gray zone.” It is not unusual for individuals to receive a diagnosis of one condition and later be found to have features of the other.

Key Differences in Symptoms

While there is considerable overlap, several clinical features help differentiate lupus from Sjögren’s syndrome:

Lupus Typically Includes:

• Skin Rashes: A classic malar (butterfly) rash that appears on the cheeks and nose.
• Photosensitivity: A tendency for the skin to react to sunlight.
• Internal Organ Involvement: Greater risk of kidney disease (lupus nephritis), cardiovascular complications, and neurological symptoms.
• Varied Systemic Manifestations: Lupus can cause inflammation in the lining of the heart or lungs (serositis) and can affect blood counts, leading to anemia or low white blood cell counts.

Sjögren’s Syndrome Often Presents With:

• Severe Dryness: Predominantly affecting the eyes and mouth, which is less common in lupus.
• Salivary and Lacrimal Gland Enlargement: Some patients may notice swelling in the glands near the jaw or eyes.
• Focused Extracutaneous Symptoms: While joint pain and fatigue occur, they are usually less severe than the multisystem involvement seen in lupus.
• Specific Autoantibodies: A stronger association with anti-Ro/SSA and anti-La/SSB antibodies is noted, particularly in primary Sjögren’s syndrome.

It’s important to note that when Sjögren’s syndrome occurs as a secondary condition (often alongside lupus), many features of both diseases can coexist, further complicating the clinical picture.

How Do Doctors Differentiate Them?

Given the overlap in symptoms, healthcare providers use a combination of clinical evaluation, laboratory tests, and imaging studies to distinguish between lupus and Sjögren’s syndrome.

Clinical Evaluation

• Medical History: Doctors review the timeline of symptoms, family history, and any triggers (such as sunlight for lupus).
• Physical Examination: Attention is paid to specific signs like the butterfly rash in lupus or glandular swelling in Sjögren’s.

Laboratory Testing

• Antinuclear Antibody (ANA) Test: A positive ANA is common in both conditions, but its pattern (such as a fine speckled pattern) can provide clues.

·  Specific Autoantibodies:

• Lupus: High titers of anti-dsDNA and anti-Sm antibodies are more specific for lupus.
• Sjögren’s: Anti-Ro/SSA and anti-La/SSB antibodies are more strongly associated with Sjögren’s.

Inflammatory Markers: Tests such as ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) can indicate systemic inflammation but are not disease-specific.

Objective Functional Tests

• Schirmer’s Test: Measures tear production to assess for dry eyes. A low tear production reading supports a diagnosis of Sjögren’s syndrome.
• Salivary Flow Rate: Quantifies saliva production; decreased flow is a key indicator of Sjögren’s.
• Salivary Gland Biopsy: In some cases, a small tissue sample from a minor salivary gland (often taken from the lip) is examined under a microscope for lymphocytic infiltration—a hallmark of Sjögren’s.

Imaging Studies

• Ultrasound of Salivary Glands: Can help identify glandular enlargement or structural changes consistent with Sjögren’s.
• Renal Ultrasound and Biopsy (if indicated): In lupus, kidney involvement is a major concern. When kidney disease is suspected, further imaging and possibly a biopsy will be performed.

Diagnostic Criteria and Guidelines

• Lupus Classification Criteria: Organizations like the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) have established criteria for diagnosing lupus. These include both clinical features and laboratory results.
• Sjögren’s Classification Criteria: Similarly, the American-European Consensus Group (AECC) and the ACR/EULAR have developed guidelines that emphasize both subjective symptoms (like dryness) and objective tests (such as Schirmer’s test and salivary gland biopsy).

By combining these different approaches, doctors can better differentiate between lupus and Sjögren’s syndrome—even when a patient presents with features of both.

When Overlap Occurs: The Overlap Syndrome

Some patients may exhibit signs of both conditions—this is known as an overlap syndrome. In overlap syndromes:

• Dual Diagnosis: Patients might be diagnosed with lupus and secondary Sjögren’s syndrome. This means that, in addition to lupus, they have objective findings of glandular dysfunction (dry eyes, dry mouth) and positive Sjögren’s-associated autoantibodies.
• Clinical Implications: Overlap syndromes can impact treatment decisions. For instance, while immunosuppressive medications are used in both conditions, the specific choice and dosage may vary based on the dominant symptoms.
• Monitoring: Patients with overlapping features require careful, regular monitoring since the pattern of organ involvement and symptom severity can evolve over time.

It’s crucial for patients to work closely with a rheumatologist who is experienced in managing overlap syndromes to ensure optimal care.

What Patients Should Know

Stay Informed

Understanding your condition is the first step toward effective management. Ask your doctor about:

• Your Specific Autoantibody Profile: Knowing whether you have anti-dsDNA, anti-Sm, anti-Ro, or anti-La antibodies can provide insight into your diagnosis.
• What Tests Were Used: Inquire about tests like the Schirmer’s test or salivary flow measurements if dryness is a significant symptom.

Be Proactive With Your Health

• Regular Follow-Ups: Autoimmune diseases can change over time. Regular appointments allow your doctor to monitor disease activity and adjust treatment as needed.
• Symptom Diary: Keeping track of your symptoms—including periods of flare-ups and remission—can help your healthcare team better understand your condition.
• Lifestyle Adjustments: A balanced, anti-inflammatory diet, regular exercise, and stress management techniques can support overall well-being and may help reduce inflammation.

Understand Treatment Options

• Medications: Both conditions are typically managed with medications such as corticosteroids, antimalarials (like hydroxychloroquine), and other immunosuppressive agents. However, the treatment plan is personalized based on your predominant symptoms.
• Symptom-Specific Therapies: For example, artificial tears and saliva substitutes can relieve dryness in Sjögren’s syndrome, while kidney involvement in lupus may require more intensive immunosuppression.
• Overlapping Treatment Strategies: If you have features of both conditions, your treatment plan might integrate approaches from both lupus and Sjögren’s management guidelines.

Seek Support

Connecting with others who understand what you’re going through can be incredibly helpful:

• Patient Support Groups: Whether online or in-person, support groups provide a space to share experiences and coping strategies.
• Educational Resources: Organizations like the Lupus Foundation and Sjögren’s Foundation offer valuable information and resources to help you stay informed.

Key takeaways

While lupus and Sjögren’s syndrome share many overlapping features, there are key differences that matter—both for diagnosis and treatment. Advances in diagnostic criteria and laboratory testing have improved our ability to distinguish between these two conditions, but the process can still be complex. The overlap syndrome, where features of both diseases coexist, underscores the importance of personalized care.

If you or a loved one has been diagnosed with an autoimmune condition, it’s important to ask questions, stay informed, and maintain open communication with your healthcare provider. Understanding the nuances of your diagnosis is a powerful step toward managing your condition and maintaining a good quality of life.

Remember, you’re not alone—support from your medical team, family, and patient communities can make a significant difference on your journey.