Allergic Necrotizing Granulomatosis - Symptoms, Diagnosis, and Treatment

Introduction:

Allergic granulomatosis is a rare disorder characterized by infiltration of lymph nodes with histiocytic granulomas and eosinophils due to isolated lymph node involvement by Churg-Strauss syndrome or allergic necrotizing granulomatosis. There will be lymph node involvement by polyarteritis nodosa (blood vessel inflammation), granulomatosis with polyangiitis (Wegener's), or lupus erythematosus. The diagnosis of Churg-Strauss syndrome is based on asthma, peripheral blood and tissue eosinophilia, and small-vessel vasculitis, which is diagnosed by tissue biopsy. Also, the presence of necrotizing granulomas associated with eosinophilic abscesses in respiratory tract biopsies is considered an indication of this disease.

What Are the Symptoms of Allergic Necrotizing Granulomatosis?

Necrotizing granulomatous inflammation (NGI) is usually caused by Mycobacterium tuberculosis.

In this, the majority of symptoms include

• Fever.

• Chest pain when inhaling or exhaling.

• Swollen and sore lymph glands.

• A persistent runny nose.

• Skin irritation is like a rash, redness, or swelling.

• Gastrointestinal problems like vomiting, diarrhea, stomach pain, bloody stool, or a painful pocket of pus near the anus.

Some of the important histopathological features are

• Necrotizing granulomas.

• Eosinophilia.

• Immunohistochemistry is typical of the reactive lymph node.

• Special stains for microorganisms are harmful.

What Is the Pathophysiology of Allergic Necrotizing Granulomatosis?

ANG is a multisystemic disorder. It has an anti-neutrophil cytoplasmic antibody (ANCA) with a small vessel with associated vasculitis. Eosinophil-rich and necrotizing granulomatous inflammation involves the respiratory tract and causes necrotizing vasculitis, predominantly affecting small to medium-sized vessels, associated with asthma and eosinophilia. EGPA pathogenesis is not well known, but it seems to be involved due to acquired pathogenetic factors, exposure to allergens, infectious diseases, vaccinations, drugs, and silica exposure. Eosinophils are the characteristic cells of this condition, and other studies have demonstrated their role as effectors and immunoregulatory cells.

ANG typically develops into three phases:

1. The Allergic Phase: It is distinguished by asthma, allergic rhinitis, and sinusitis symptoms.

2. In The Eosinophilic Phase: The main pathological finding in this stage is the eosinophilic organ infiltrations, for example, lungs, heart, and gastrointestinal system.

3. The Vasculitic Phase: This stageis characterized by purpura (occurs when small blood vessels burst), peripheral neuropathy (damage of the nerve inside and outside the brain), and constitutional symptoms like fever, anorexia (eating disorder), headache, and malaise.

What Is the Clinical Feature of Allergic Necrotizing Granulomatosis?

• Eosinophilic granulomatosis is a disease caused by inflammation or swelling in certain blood cells or tissues with polyangiitis, which is the inflammation of multiple types of vessels, such as small arteries and veins, mainly affecting patients with asthma, sinusitis, allergic rhinitis, and nasal polyposis.

• The first phase is also called prodromic. It is common in the second and third decades. It is characterized by asthma, sinusitis, and allergic rhinitis. Later the eosinophilic phase develops. The main pathological findings are the increased peripheral eosinophil count and the eosinophilic organ infiltrations, especially in the lungs, heart, and gastrointestinal systems. The third phase is vasculitic. During this phase, the patient bears the consequences of necrotizing vasculitis (inflammation and degeneration of blood cells), which is associated with vascular or extravascular granulomatosis and symptoms like fever, malaise, headache, and weight loss.

• The respiratory system is one of the most affected, where asthma prevalence is more than 95 %. Pulmonary eosinophils invade the cells and hence it is present, and their biopsy is often highly instructive for the histopathologic diagnosis.

• The otorhinolaryngologic system is also affected. Nasal polyposis is one condition that leads patients to undergo consecutive surgery. Allergic rhinosinusitis, epistaxis, and neurosensory hearing loss are other features.

• Cardiac involvement may be involved and demonstrates the most toxic manifestation of ANG, which is distinguished by, pericarditis, heart attacks, or congestive heart failure leading to death.

• Subcutaneous nodules and purpura represent the vasculitic phase among the most skin manifestations. A skin biopsy of purpuric lesions shows leukocytoclastic vasculitis.

• Peripheral neuropathy, both sensory, motor, or sensory-motor, affects a large portion of the patients; mono neuritis, with axonal damage, usually unilateral and asymmetric, is the typical manifestation of the peripheral nervous system and its involvement. Patients tend to have paresthesia and pain in the affected areas like the peroneal, tibial, and ulnar nerves, especially during the vasculitic stage of the disease.

• The vasculitic phase may be preceded by eosinophilic gastroenteritis with abdominal pain, diarrhea, and intestinal bleeding in the gastrointestinal system.

How Do We Diagnose ANG?

• Neutrophil Function Tests: Your doctor may conduct a dihydroergotamine 123 (DHR) test or other tests to check the functional efficacy of white blood cells (neutrophils). Doctors usually use this test to diagnose granulomatosis.

• Genetic Testing: Genetic testing confirms the presence of a specific genetic mutation that results in granulomatous disease.

• Prenatal Testing: Prenatal testing is to diagnose if one of your children has already been diagnosed with GD.

What Are the Treatment Options for Allergic Necrotizing Granulomatosis?

Treatment for ANG is aimed at helping you avoid infections and manage your condition. Treatments may include:

• Infection Management: It is essential to prevent bacterial and fungal infections before they occur. Treatment includes antibiotic therapy, like trimethoprim and sulfamethoxazole combination, to be immune to bacterial infections. And itraconazole to prevent fungal infection.

• Medications: Additional antibiotics or antifungal medications are necessary if the infection increases.

• Interferon-Gamma: Interferon-gamma injections are given periodically, which may help boost cells and the immune system to fight infections.

• Stem Cell Transplantation: A stem cell transplant can come up with a cure for granulomatosis in some cases. This treatment depends on prognosis, donor availability, and personal preference.

Conclusion:

Therefore, allergic necrotizing granulomatosis is a rare ailment characterized by peripheral eosinophilia, hepatosplenomegaly, dyspnea, and lymphadenopathy. They should be diagnosed early to be given the proper treatment. Some options are antibiotics and stem cell therapy.