Eosinophilic Granulomatosis with Polyangiitis (EGPA)

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome, is a rare autoimmune disorder characterized by the presence of asthma, high levels of eosinophils, and vasculitis (inflammation of blood vessels).

Causes and Risk Factors

The exact cause of EGPA is unknown, but it is believed to be related to an abnormal immune response. The condition is often associated with a history of asthma or allergies, and may be triggered by certain factors such as:

• Infections
• Medications (e.g., leukotriene modifiers)
• Allergens (e.g., pollen, dust mites)

Symptoms

The symptoms of EGPA can vary widely and may include:

• Asthma-like symptoms (wheezing, coughing, shortness of breath)
• Eosinophilia (high levels of eosinophils in the blood or tissues)
• Vasculitis (inflammation of blood vessels), which can affect various organs such as:
• Skin (rash, purpura)
• Kidneys (nephritis)
• Nervous system (neuropathy, seizures)
• Heart (cardiomyopathy, heart failure)
• Fever
• Weight loss
• Fatigue

Diagnosis

The diagnosis of EGPA is based on a combination of clinical findings, laboratory tests, and imaging studies. The following criteria are often used to diagnose EGPA:

• Asthma
• Eosinophilia (≥10% eosinophils in the blood or tissues)
• Vasculitis (inflammation of blood vessels) affecting at least two organs

Laboratory tests may include:

• Complete blood count (CBC) to evaluate eosinophil levels
• Blood chemistry tests to assess kidney and liver function
• Imaging studies (e.g., chest X-ray, CT scan) to evaluate organ involvement

Treatment

The treatment of EGPA typically involves a combination of medications to control inflammation, suppress the immune system, and manage symptoms. The following medications may be used:

• Corticosteroids (e.g., prednisone) to reduce inflammation
• Immunosuppressants (e.g., cyclophosphamide, azathioprine) to suppress the immune system
• Biologics (e.g., mepolizumab) to target specific molecules involved in the disease process
• Asthma medications (e.g., bronchodilators, inhaled corticosteroids) to manage asthma-like symptoms

Prognosis and Complications

The prognosis of EGPA varies depending on the severity of the disease and the response to treatment. If left untreated, EGPA can lead to serious complications such as:

• Organ damage (e.g., kidney failure, heart failure)
• Infections
• Malignancies (e.g., lymphoma)

With proper treatment, many patients with EGPA can achieve remission and lead active lives. However, the condition requires ongoing monitoring and management to prevent relapses and complications.