Cohort Definition Name: “Overlap syndrome”
Contributor name: Joel N. Swerdel
Contributor OrcId: 0000-0001-9491-2737
Logic Description: First occurrence of Overlap syndrome.
Recommended study application: outcome, indication
Assertion statement: This cohort definition was executed on at least one real person-level observational health data source and resulted in a cohort with at least 1 person.
Submitted cohort definition:
overlap.txt (1.9 KB)
Target Clinical Description
Overlap syndrome refers to a complex condition characterized by the presence of clinical features and autoantibodies that overlap multiple autoimmune connective tissue diseases, such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM), and/or rheumatoid arthritis (RA). It represents an intermediate form between distinct autoimmune diseases, sharing common features and demonstrating a mixed clinical and serological profile. Overlap syndrome can present unique challenges in terms of diagnosis and management due to the variability and complexity of symptoms. The exact cause of overlap syndrome is unknown, but it is believed to involve a combination of genetic, environmental, and immunological factors. Early recognition, comprehensive assessment, and tailored treatment approaches are essential in managing this condition effectively.
Presentation for Overlap syndrome:
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Joint pain and swelling: Similar to rheumatoid arthritis, individuals with overlap syndrome may experience symmetrical joint involvement, morning stiffness, and joint deformities.
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Skin manifestations: Skin abnormalities such as malar rash (butterfly rash), discoid rash, photosensitivity, or Raynaud’s phenomenon, which are common in systemic lupus erythematosus and systemic sclerosis.
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Muscle weakness: Muscle weakness, fatigue, and myalgias resembling polymyositis.
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Lung involvement: Interstitial lung disease, pulmonary hypertension, or pleuritis, which can be seen in systemic sclerosis or other connective tissue diseases.
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Raynaud’s phenomenon: Cold-induced color changes in the fingers or toes due to vasospasm.
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Gastrointestinal symptoms: Gastrointestinal involvement, including esophageal dysmotility, gastroesophageal reflux disease (GERD), or bowel abnormalities, seen in systemic sclerosis.
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Renal abnormalities: Proteinuria, hematuria, or renal inflammation as observed in systemic lupus erythematosus or other connective tissue diseases.
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Cardiac manifestations: Pericarditis, myocarditis, or heart conduction abnormalities.
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Constitutional symptoms: Fatigue, fever, weight loss, and general malaise.
Assessment for Overlap syndrome:
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Detailed medical history and physical examination: Evaluation of symptoms, assessment of joint involvement, skin changes, muscle strength, and signs of organ involvement.
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Autoantibody testing: Detection of specific autoantibodies associated with different autoimmune connective tissue diseases, such as antinuclear antibodies (ANA), anti-dsDNA antibodies, anti-Smith antibodies (SLE), anti-centromere antibodies (SSc), or anti-Jo-1 antibodies (PM).
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Laboratory tests: Complete blood count, kidney and liver function tests, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and other inflammatory markers.
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Imaging studies: Depending on the specific symptoms, imaging tests such as X-rays, ultrasound, or computed tomography (CT) scans may be performed to assess organ involvement or damage.
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Specialized tests: Electromyography, skin biopsy, lung function tests, or specific organ-related tests may be conducted based on individual presentation and suspected organ involvement.
Differential diagnoses for Overlap syndrome:
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Systemic lupus erythematosus (SLE)
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Systemic sclerosis (SSc)
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Polymyositis (PM)
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Rheumatoid arthritis (RA)
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Mixed connective tissue disease (MCTD)
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Other autoimmune or connective tissue diseases with overlapping features
Treatment plan for Overlap syndrome:
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Individualized approach: Treatment plans may vary based on the predominant clinical features and organ involvement. A multidisciplinary team, including rheumatologists, dermatologists, pulmonologists, and other specialists, collaborates to develop a comprehensive and tailored treatment strategy.
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Medications: Immunosuppressive drugs, such as corticosteroids, disease-modifying antirheumatic drugs (DMARDs), and biologic agents, may be prescribed to control inflammation, manage symptoms, and prevent organ damage.
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Symptom-specific interventions: Treatment for specific manifestations such as joint pain, skin involvement, pulmonary complications, or gastrointestinal symptoms may include nonsteroidal anti-inflammatory drugs (NSAIDs), antimalarials, immunomodulatory medications, proton pump inhibitors, or specialized therapies.
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Supportive care: Physical therapy, occupational therapy, and lifestyle modifications may be recommended to manage symptoms, improve functional abilities, and enhance overall quality of life.
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Regular monitoring: Ongoing monitoring of disease activity, organ function, and medication side effects is crucial to adjust the treatment plan as needed.
Prognosis for Overlap syndrome: The prognosis of overlap syndrome varies depending on the specific clinical features, extent of organ involvement, and response to treatment. Early diagnosis, appropriate management, and close monitoring can help control symptoms, prevent complications, and improve long-term outcomes. However, the course of overlap syndrome can be unpredictable, and individuals may experience periods of disease flares and remission. With proper medical care and adherence to treatment plans, many individuals with overlap syndrome can achieve symptom control and maintain a good quality of life. Regular follow-up and collaboration with healthcare providers are essential to address evolving needs and optimize the prognosis.