### Date : 2024-11-06 16:35 ### Topic : Churg-Strauss Syndrome (EGPA) #pulmonology ---- **Churg-Strauss Syndrome (CSS)**, now commonly known as **Eosinophilic Granulomatosis with Polyangiitis (EGPA)**, is a rare form of **small to medium vessel vasculitis** that primarily affects people with a history of asthma or allergies. EGPA is characterized by **elevated eosinophils**, **allergic inflammation**, and **vascular inflammation** (vasculitis), which can damage multiple organs, especially the lungs, skin, and peripheral nerves. ### Pathophysiology of Churg-Strauss Syndrome (EGPA) EGPA is an autoimmune disease involving an overactive immune response, where **eosinophils** (a type of white blood cell involved in allergic reactions) infiltrate and damage tissues. The exact cause is unknown, but environmental factors, genetic predisposition, and certain medications have been implicated as potential triggers. EGPA progresses through three stages: 1. **Allergic Stage**: - This stage is marked by **asthma** and **allergic rhinitis** (nasal allergy symptoms). - Most individuals with EGPA have asthma, which often precedes other symptoms by several years. 2. **Eosinophilic Stage**: - In this stage, there is a marked increase in **eosinophils** in the blood and tissues, causing eosinophilic infiltration, particularly in the lungs and gastrointestinal tract. - Symptoms may include fever, weight loss, abdominal pain, and pulmonary infiltrates, mimicking pneumonia or other lung diseases. 3. **Vasculitic Stage**: - The final stage is characterized by **vasculitis** of small to medium blood vessels, leading to organ damage due to reduced blood flow. - Vasculitis can affect multiple organs, including the skin, nerves, heart, kidneys, and digestive tract, causing diverse symptoms. ### Symptoms of Churg-Strauss Syndrome Symptoms vary widely depending on the organs involved and the stage of disease. They often include a combination of respiratory, systemic, and organ-specific manifestations: 1. **Respiratory Symptoms**: - **Asthma**: The most common and often the first symptom; can range from mild to severe. - **Allergic rhinitis**: Nasal congestion, runny nose, and sinus issues. - **Lung infiltrates**: Eosinophilic infiltration can cause cough, shortness of breath, and transient lung infiltrates that may look like pneumonia on imaging. 2. **Constitutional Symptoms**: - **Fever**, **weight loss**, **fatigue**, and **malaise** are common, especially during disease flares. 3. **Skin Manifestations**: - **Purpura** (small purple spots due to bleeding under the skin), **nodules**, and **rashes** are common, particularly on the legs. 4. **Peripheral Neuropathy**: - Nerve involvement, such as **mononeuritis multiplex** (affecting multiple individual nerves), can lead to **pain, numbness, or weakness** in the arms or legs. 5. **Gastrointestinal Symptoms**: - Eosinophilic inflammation in the GI tract can cause **abdominal pain, diarrhea, nausea, and vomiting**. 6. **Cardiac Involvement**: - Heart complications include **myocarditis**, **pericarditis**, and **heart failure**, which are serious and can be life-threatening in EGPA. 7. **Renal Involvement**: - Though less common than in other vasculitis forms, kidney disease can occur and may lead to **glomerulonephritis**. ### Diagnosis of Churg-Strauss Syndrome Diagnosis is based on clinical findings, laboratory tests, and imaging studies, and may include: 1. **Blood Tests**: - **Eosinophilia**: Elevated eosinophil counts are a hallmark of EGPA. - **Elevated IgE**: Immunoglobulin E (IgE) levels are often high due to allergic response. - **Antineutrophil Cytoplasmic Antibodies (ANCA)**: Present in about 40% of patients, especially those with more vasculitic involvement. **p-ANCA** (perinuclear ANCA, often with MPO antibodies) is the most common pattern seen in EGPA. 2. **Imaging**: - **Chest X-ray or CT Scan**: May show lung infiltrates, nodules, or areas of atelectasis. - **Sinus Imaging**: Chronic sinusitis may be observed on CT scans of the sinuses. 3. **Biopsy**: - A biopsy of affected tissue (e.g., lung, skin, nerve) can confirm the diagnosis by showing eosinophilic inflammation and granulomas within blood vessels. 4. **Pulmonary Function Tests (PFTs)**: - May show an obstructive pattern similar to asthma, with reduced airflow due to airway inflammation. ### Treatment of Churg-Strauss Syndrome Treatment of EGPA focuses on controlling inflammation, reducing eosinophil levels, and preventing organ damage. Treatment usually involves: 1. **Corticosteroids**: - **Prednisone** is the mainstay of treatment to control inflammation and reduce eosinophil levels. - High doses are used initially, with a gradual taper once symptoms improve. Long-term maintenance therapy may be required for some patients. 2. **Immunosuppressive Agents**: - **Cyclophosphamide**: Used for severe cases or when vital organs are involved (e.g., heart, kidneys, or nervous system). - **Azathioprine** or **Methotrexate**: Often used for maintenance therapy after initial treatment with corticosteroids and/or cyclophosphamide. 3. **Biologic Agents**: - **Mepolizumab** and **Benralizumab**: Monoclonal antibodies that target **IL-5**, a key cytokine in eosinophil activation and survival. These biologics are used in patients with refractory or corticosteroid-dependent EGPA and help reduce eosinophil counts. - **Rituximab**: Occasionally used, especially in ANCA-positive cases or if there is vasculitis affecting multiple organs. 4. **Management of Asthma and Allergies**: - Inhaled corticosteroids, bronchodilators, and other asthma medications are used to manage respiratory symptoms. - Antihistamines or nasal sprays may help with allergic rhinitis. 5. **Supportive Care**: - Physical therapy or rehabilitation for nerve damage. - Regular monitoring of heart, lung, and kidney function to detect any disease progression or complications early. ### Prognosis and Complications The prognosis of EGPA depends on the extent of organ involvement and response to treatment. With appropriate treatment, many patients experience significant symptom relief and disease control, although relapses are common. Potential complications include: - **Organ Damage**: Particularly in the heart and peripheral nerves, which can lead to long-term deficits. - **Chronic Medication Side Effects**: Prolonged corticosteroid use can lead to complications such as osteoporosis, diabetes, and infections. - **Relapses**: EGPA often has a relapsing-remitting course, requiring long-term follow-up and possible adjustments in therapy. ### Summary - **Churg-Strauss Syndrome (EGPA)** is a rare vasculitis associated with asthma, eosinophilia, and inflammation of small to medium blood vessels. - **Symptoms** include asthma, sinusitis, skin lesions, neuropathy, and possible heart, GI, or kidney involvement. - **Diagnosis** relies on clinical presentation, eosinophilia, ANCA testing, and often biopsy. - **Treatment** involves corticosteroids, immunosuppressants, and biologics targeting eosinophils. Early diagnosis and prompt treatment of EGPA are crucial to prevent serious complications and improve the quality of life for affected patients. Regular monitoring and adjusting the treatment as needed can help manage this complex, multi-organ disease. ### Reference: - ### Connected Documents: -