Churg-Strauss Syndrome

Origin

Churg-Strauss syndrome is the former name for eosinophilic granulomatosis with polyangiitis (EGPA). It was first described by Jacob Churg and Lotte Strauss in 1951 based on the autopsy findings of patients.

The synonymous terms of Churg-Strauss syndrome are mentioned below;

• Allergic angiitis and granulomatosis.

• Allergic granulomatosis.

• Allergic granulomatosis and angiitis.

• Churg-Strauss vasculitis.

What Is Churg-Strauss Syndrome?

Churg-Strauss syndrome is an autoimmune disorder wherein there is inflammation of small and medium-sized blood vessels (vasculitis or angiitis), especially of the skin, lungs, abdomen, and nerves. It usually occurs in people with a history of allergy or asthma and affects multiple organ systems.

The characteristics of this condition are,

• Hypereosinophilia - There is an abnormal clustering of eosinophils (one type of white blood cell) in the blood and tissues.

• Vasculitis - Inflammation of the blood vessels.

• Granulomatosis - Development of granulomas (inflammatory nodular lesions).

What Are the Signs and Symptoms of Churg-Strauss Syndrome?

Churg-Strauss syndrome affects multiple organs of the body, hence the symptoms also vary from one person to another based on the organ affected. Three phases of the syndrome exist based on which symptoms also vary.

They are;

1. Prodromal (or Allergic) Phase - The prodromal phase of the condition can linger for months to years and result in blood vessel inflammation of the affected region as early as six months or as late as two decades. Respiratory symptoms usually develop initially in Churg-Strauss syndrome.

As the name indicates, allergic reactions develop in this phase.

• Late-onset asthma.

• Cough.

• Wheezing.

• Shortness of breath (dyspnea).

• In those with preexisting asthma, it can worsen.

• Allergic rhinitis (symptoms include runny nose, nasal obstruction, sneezing, and itching due to inflammation of the nasal mucous membrane).

• Sinusitis (inflammation of the sinus).

• Facial pain.

• Nasal polyp formation due to chronic inflammation of the nose.

2. Eosinophilic Phase - In this phase of this syndrome, eosinophils, a type of white blood cell, are produced in abnormally excessive amounts (hypereosinophilia) and accumulate in various tissues of the body, especially in the lung, gastrointestinal, and skin tissues. These eosinophils are produced in response to allergies in the body.

3. Vasculitic Phase - This phase of Churg-Strauss syndrome is characterized by blood vessel inflammation (swelling) in various regions of the body. When this blood vessel inflammation (vasculitis) persists for a longer duration, (chronic) narrowing of the blood vessels occurs. This results in,

• Slowing down blood flow.

• Blockage in blood flow to a particular part of the body.

• Thinning and fragility of the affected blood vessel.

• Rupturing of the blood vessel and bleeding into the surrounding tissues.

• Stretching of blood vessels and formation of a bulge or aneurysm.

These three phases need not occur sequentially and compulsorily in all affected people.

Other nonspecific symptoms include,

• Fatigue.

• Cough.

• Fever.

• Malaise (feeling of illness).

• Generalized weakness.

• Weight loss.

• Night sweats.

• Joint pain (arthralgia).

• Abdominal pain.

• Muscle pain (myalgia).

How Does Churg-Strauss Syndrome Affect Different Organs?

1. Lymph Nodes - Enlargement of lymph nodes occur. Swollen lymph nodes and generalized weakness have also been reported.

2. Ear - Middle ear infections (otitis media) and fluid build-up occur, resulting in hearing loss.

3. Eyes - Inflammation of the conjunctiva occurs.

4. Neurological System - A condition called mononeuritis multiplex can develop, wherein two or more nerves in separate areas of the peripheral nervous system (nerves found outside the brain and spinal cord) can get damaged or affected, leading to symptoms like,

• Pain.

• Tingling or numbness sensation.

• Weakness.

• Muscle wasting in the hands and feet.

Polyneuropathy (multiple nerves in the same area of the body get affected) also occurs, which, when untreated, can prove life-threatening.

5. Skin - The accumulation of eosinophils in the skin causes the following symptoms;

• Purpura (purplish skin due to bleeding underneath).

• Urticaria.

• Nodules on the skin.

6. Gastrointestinal System -

• Abdominal pain.

• Nausea.

• Vomiting.

• Diarrhea.

• Bloody stools.

• Colitis (inflammation of the colon).

7. Heart - The syndrome can cause the following heart problems (due to inflammation of heart blood vessels and formation of nodular lesions in heart tissues), which can result in symptoms like chest pain, chest flutters, fatigue, shortness of breath, and fainting.

• Pericarditis (inflammation of the sac surrounding the heart).

• Myocarditis (inflammation of the muscular wall of the heart).

• Heart failure.

• Heart attack.

8. Kidney - Inflammation of the capillaries of the kidney that filters the blood in kidneys called glomerulonephritis can develop. This can eventually lead to kidney failure.

What Causes Churg-Strauss Syndrome?

In Churg-Strauss syndrome, there is an exaggerated and abnormal immune system activity to some unclear triggers (medications, infections, etc.). The exact cause is not clear, but multiple factors are speculated to cause this syndrome.

• Exposure to industrial solvents.

• Infections.

• Autoimmunity.

• Medications (Zafirlukast therapy).

• Genetics (least suspected cause).

How Common Is Churg-Strauss Syndrome?

It is a rare condition with upto 14 per million people being affected worldwide. Susceptible people around the age of 40 are frequently affected; however, the prevalent age group ranges from the late 30s to early 50s.

How Is Churg-Strauss Syndrome Diagnosed?

Physicians suspect the syndrome in asthma patients who report the above-discussed symptoms. The diagnosis for Churg-Strauss syndrome is purely clinically made (symptom-based), and other additional investigatory tests help confirm the diagnosis.

• Skin Biopsy - Though not specific to this syndrome, skin biopsy reveals vasculitis, which is supportive in diagnosis. A thorough physical examination will help identify the skin lesions.

• Blood Tests - Complete blood count and differential count help reveal elevated white blood cells and eosinophils. Kidney function tests will be ordered in case of renal symptoms.

• Urinalysis - If your physician suspects your kidney is affected, they may order a urine test.

• Pulmonary Function Test (PFT) - PFT shows lung (airflow) obstruction.

• CT (Computed Tomography) of the Chest and Sinus - CT of the chest and sinus shows thickening of the nasal membrane and sinus walls, lung infiltrates, bronchial wall thickening,

• Sural Nerve Biopsy - Axonal degeneration is present indicative of peripheral neuropathy. Sural nerve biopsy is regarded as the gold standard for Churg-Strauss diagnosis.

What Treatment Helps Manage Churg-Strauss Syndrome?

Suppressing the immune system and treating the blood vessel inflammation remains the main treatment approach. For that purpose, the following drugs are used;

• Steroids - High doses of steroids like Prednisone are used to tackle the inflammation, which is usually tapered in the following months.

• Cyclophosphamide - This drug is used for about 6 to 12 months (can vary from 1 to 2 years) to suppress the immune system.

What Is the Prognosis of Churg-Strauss Syndrome?

Before the advent of Prednisone, Churg-Strauss syndrome was a fatal condition. But early detection and usage of steroids and immunosuppressants can help quieten the inflammation and improve the symptoms. If untreated, it can affect multiple organs in the body and prove dangerous due to complications like stroke, cardiac diseases, etc.