Medical History & Social Background

The patient has no prior history of rheumatoid arthritis or lupus, but her mother had systemic lupus erythematosus (SLE). She works in an office and denies smoking or alcohol use. She has had multiple doctor visits in the past year for unexplained fatigue and joint pain, but no definitive diagnosis has been made.

Physical Examination

• Swollen, stiff, and tender joints, particularly in the fingers, wrists, and knees.

• Raynaud’s phenomenon with bluish discoloration of fingers in cold temperatures.

• Mild muscle weakness in the shoulders and thighs.

• Skin tightening (sclerodactyly) and digital ulcers on the fingertips.

• Malar rash and photosensitivity on the face.

• Mild inspiratory crackles on lung auscultation.

Laboratory & Imaging Findings

• Antinuclear antibody (ANA): Strongly positive (1:160, speckled pattern).

• Anti-U1 RNP antibodies: Positive.

• Anti-dsDNA, anti-Smith, anti-CCP, and anti-Scl-70: Negative.

• Elevated creatine kinase (CK) levels, indicating muscle inflammation.

• Mild anemia and raised inflammatory markers (ESR, CRP).

• Hand X-ray: Mild periarticular osteopenia, no erosions.

• Pulmonary function tests (PFTs): Reduced diffusion capacity, suggesting early interstitial lung disease.

Diagnosis

The patient's clinical presentation and laboratory findings suggest mixed connective tissue disease (MCTD), a form of overlap syndrome, characterized by features of systemic lupus erythematosus (SLE), systemic sclerosis (scleroderma), and polymyositis. Because she has clear autoantibodies (anti-U1 RNP) but does not fully meet the criteria for any one disease alone, her condition falls under MCTD rather than undifferentiated connective tissue disease (UCTD).

Management Plan

1. Symptomatic Treatment

• Nonsteroidal anti-inflammatory drugs (NSAIDs) for joint pain and inflammation.

• Calcium channel blockers (e.g., nifedipine) for Raynaud’s phenomenon.

• Proton pump inhibitors (PPIs) for gastroesophageal reflux symptoms due to esophageal involvement.

2. Disease-Modifying Treatment

• Corticosteroids (low-to-moderate dose) for muscle inflammation and arthritis.

• Methotrexate or azathioprine for systemic inflammation and lung involvement.

• Consider rituximab or mycophenolate mofetil if lung disease worsens.

3. Monitoring & Long-Term Care

• Regular pulmonary function tests to track lung involvement.

• Routine echocardiography to check for pulmonary hypertension.

• Ongoing assessment for new symptoms, including kidney and neurological involvement.

• Patient education on avoiding cold exposure for Raynaud’s phenomenon and recognizing early signs of disease progression.

Challenges & Considerations

• High variability in symptoms makes early diagnosis difficult.

• Risk of organ involvement (lungs, heart, kidneys) over time.

• Emotional and psychological impact, requiring support and counseling.

Prognosis

With early intervention and careful monitoring, the patient can have a stable disease course. However, lung involvement or progressive skin tightening may lead to long-term complications, requiring more aggressive therapy.