Eosinophilic Granulomatosis With Polyangiitis - Signs and Symptoms, Complications, Diagnosis, and Treatment

Introduction

Eosinophilic granulomatosis with polyangiitis is a rare autoimmune disease that is also referred to as allergic granulomatosis. It is also referred to as Churg-Strauss syndrome. It usually occurs in people with asthma or allergy. It is characterized by an increase in the level of eosinophils. It affects the lungs, gastrointestinal tract, skin, heart, and nervous system.

What Is Eosinophilic Granulomatosis With Polyangiitis?

Eosinophilic granulomatosis with polyangiitis is a rare disease that affects individuals with a history of airway allergic hypersensitivity. It results in vasculitis (inflammation of small and medium-sized blood vessels). It occurs in three stages. The prodromal stage is the early stage characterized by airway inflammation in individuals with asthma or allergic rhinitis. The second stage is hypereosinophilia which causes an increase in eosinophil count. This increased eosinophil count results in lung and digestive tissue damage. The third stage is vasculitis, which eventually causes cell death and life-threatening complications.

What Are Eosinophils?

Eosinophils are a type of white blood cell that constitutes 5% or less than the total white blood cell count. In eosinophilic granulomatosis, the count increases, and eosinophils comprise of more than 10 % of the total WBC count.

What Does Vasculitis Mean?

Vasculitis means blood vessel inflammation. The blood vessels become inflamed and develop an aneurysm (abnormal blood-filled enlargement of the blood vessel). The blood vessel walls become thin and rupture, resulting in blood leaking into the tissue. The blood vessels can narrow and result in low oxygen and nutrient supply.

What Are the Effects of Eosinophilic Granulomatosis With Polyangiitis?

It affects people of all ages. The cause of the disease is not known. The immune system, responsible for protecting against infections, diseases, and other injuries, becomes overactive and results in inflammation. The inflammation injures the lungs, nose, sinuses, skin, joints, nerves, gastrointestinal tract, heart, kidneys, and sometimes the brain.

What Are the Signs and Symptoms Associated With Eosinophilic Granulomatosis With Polyangiitis?

Eosinophilic granulomatosis comprises three stages. However, all patients do not develop all three stages or progress from one stage to the other in order.

The symptoms of each stage include:

• Allergic Stage - The prodromal stage is the early stage characterized by allergic rhinitis and asthma. Allergic rhinitis causes symptoms like rhinorrhea, sinusitis, and nasal obstruction. Nasal polyps formation is also present. In addition, shortness of breath, chest pain, rashes on the skin, muscle and joint pain, facial pain, abdominal pain, blood in the stools, numbness, or loss of strength may be present.

• Eosinophilic Stage - The second stage is characterized by an increase in the eosinophil count in the blood. It is due to abnormal eosinophil proliferation, impaired apoptosis, and increased toxicity due to eosinophil metabolites. An increase in eosinophils is responsible for the pathogenesis of asthma in the allergic stage. It initiates and maintains immune responses in inflammation. Hypereosinophilia commonly affects the lungs and the digestive tract.

• Vasculitic Stage - The vasculitic stage is the third stage characterized by blood vessel inflammation and blood flow reduction to the organs and tissues. It is due to the abundant eosinophils circulating throughout the body's vasculature.

What Are the Complications of Eosinophilic Granulomatosis With Polyangiitis?

All patients do not develop complications. It may be seen in some cases. Blood clots develop in the damaged arteries, usually in the abdominal region, leading to infarcts, cell death, or slow atrophy. Peritonitis, ulcerations, and perforations of the gastrointestinal tract can occur. Inflammation of the heart muscle occurs due to the high level of eosinophils. Kidney complications like glomerulonephritis prevent the ability to filter the waste and cause waste buildup in the bloodstream.

How Is Eosinophilic Granulomatosis With Polyangiitis Diagnosed?

Diagnosis is based on diagnostic markers like eosinophil granulocytes and granulomas in the affected tissue and antineutrophil cytoplasmic antibodies against the neutrophil granulocytes. The American College of Rheumatology 1990 framed diagnostic criteria for eosinophilic granulomatosis with polyangiitis, which include:

• Asthma.

• Hypereosinophilic.

• Mononeuropathy or polyneuropathy.

• Unfixed pulmonary infiltrates.

• Presence of paranasal sinus abnormalities.

• Histological evidence of extravascular eosinophils.

The presence of any four of the above criteria indicates a positive diagnosis.

• Blood Tests - This is performed to check the presence of an increase in eosinophil count. An antineutrophil cytoplasmic antibodies (ANCA) test is performed to diagnose autoimmune vasculitis.

• Urinalysis may be done to check the urinary protocols.

• Radiographic Imaging - CT (computed tomography) scan of the lungs shows parenchymal opacification or ground glass opacity in the middle and lower zones. Interlobular septal thickening is seen due to the septa' separation of secondary pulmonary lobules due to pulmonary edema.

• Biopsy - Biopsy is not required in all cases and is performed when laboratory tests or imaging tests are abnormal. It is done to identify eosinophils, eosinophilic granulomas, and vasculitis.

How Is Eosinophilic Granulomatosis With Polyangiitis Treated and Managed?

Eosinophilic granulomatosis with polyangiitis can be treated and managed by the following criteria

• Corticosteroids: Primary treatment often involves high-dose corticosteroids like prednisone to reduce the inflammation faster.

• Immunosuppressive Drugs: Medications like Rituximab or cyclophosphamide may be added to prevent relapse and reduce the immune response.

• Long-Term Steroid Tapering: Once the symptoms are controlled, a gradual lowering of steroids is typically done to reduce the side effects.

• Symptomatic Relief: Medications like bronchodilators and antihistamines may be prescribed for symptom relief which is used to address problems like itching and respiratory symptoms.

• Managing Complications: Treatment plans consider and manage complications like kidney involvement, heart tissue, and nerve damage.

• Monitoring: Regular monitoring and checkups of blood markers help in identifying disease progression and adjust the treatment accordingly.

• Lifestyle Changes: Smoking cessation is important as it triggers the problem. Individuals should manage stress and maintain a healthy lifestyle.

• Support and Education: Patient education about the disease, side effects, and medications is important.

• Personalized Treatment Plans: EGPA treatment approaches may vary based on disease severity, organ involvement, and the patient's overall health, requiring a personalized and adaptive strategy.

Conclusion

Eosinophilic granulomatosis with polyangiitis is a serious disease that cannot be prevented. It progresses to affect various organs of the human body. However, serious complications can be prevented by early diagnosis and treatment. Early intervention plays a significant role in limiting the damage to the organs and the progression of the disease.