Churg-Strauss Syndrome (CSS), also known as Eosinophilic Granulomatosis with Polyangiitis (EGPA), is a rare form of vasculitis - a disease that causes inflammation of the blood vessels. The hallmark of CSS is the abnormal accumulation of eosinophils, a type of white blood cell associated with allergic reactions and asthma. These eosinophils can invade various organs and tissues, leading to a wide range of symptoms, some of which can be life-threatening.
The impact of Churg-Strauss Syndrome on the body depends on the organs that are affected, which can vary widely from patient to patient. Let's explore how this disease can affect different systems in the body, particularly the lungs, heart, skin, gastrointestinal tract, nervous system, and kidneys.
One of the most frequently affected organs in Churg-Strauss Syndrome is the lungs. Nearly all individuals with CSS have asthma, which is often the first sign of the disease. The involvement of the lungs is due to the accumulation of eosinophils and inflammation, which can manifest in several ways.
Asthma is present in approximately 90% of patients with CSS. For many, asthma appears years before other symptoms, and in some cases, it may worsen suddenly when CSS develops. Asthma in CSS is usually chronic and can be challenging to manage, even with standard treatments. Some individuals may experience new-onset asthma that becomes severe rapidly, often resistant to traditional asthma medications.
In addition to asthma, individuals with CSS may develop pulmonary infiltrates, areas of the lung that become filled with fluid, white blood cells, or other substances due to inflammation. These infiltrates can mimic pneumonia on imaging tests like chest X-rays, although they are not caused by an infection. This can lead to symptoms such as shortness of breath, coughing, and chest pain. In some cases, the pulmonary infiltrates can resolve on their own or with treatment, while in others, they can persist and lead to lung damage.
In some patients, CSS can lead to pleural effusion, a condition in which fluid accumulates in the space between the lungs and the chest wall (the pleura). This fluid buildup can cause difficulty breathing, chest pain, and a feeling of heaviness in the chest. Pleural effusion requires medical attention, and in severe cases, the fluid may need to be drained.
Cardiac involvement in Churg-Strauss Syndrome is one of the most serious and potentially life-threatening aspects of the disease. When eosinophils invade the heart, they can cause inflammation of the heart muscle (myocarditis), the lining around the heart (pericarditis), or the blood vessels that supply the heart.
Eosinophilic myocarditis is an inflammation of the heart muscle caused by an overabundance of eosinophils. This inflammation can lead to scarring, weakening of the heart muscle, and reduced ability of the heart to pump blood effectively. Symptoms of myocarditis can include fatigue, shortness of breath, irregular heartbeats, and chest pain. If left untreated, myocarditis can lead to heart failure.
Some patients may develop pericarditis, an inflammation of the pericardium, which is the protective sac that surrounds the heart. This can cause sharp chest pain that worsens with breathing or lying down. In severe cases, pericarditis can lead to a condition called cardiac tamponade, where fluid builds up in the pericardium, compressing the heart and impeding its ability to function properly. This is a medical emergency that requires immediate treatment.
Churg-Strauss Syndrome can also cause inflammation of the blood vessels that supply the heart, a condition known as coronary vasculitis. This can reduce blood flow to the heart muscle, potentially leading to angina (chest pain) or even a heart attack in severe cases.
The skin is another organ commonly affected by Churg-Strauss Syndrome. Skin manifestations occur in up to 70% of patients and are typically the result of blood vessel inflammation and eosinophilic infiltration. Skin symptoms may vary, but some of the most common findings include:
Skin rashes are a frequent feature of CSS, often appearing as red or purplish spots called petechiae or larger raised areas called purpura. These rashes are the result of blood leaking from inflamed blood vessels into the surrounding skin. The rash may appear on the legs, arms, or trunk, and it can be itchy or painful.
Some individuals with CSS develop subcutaneous nodules, small lumps under the skin caused by inflammation or the formation of granulomas. These nodules are usually firm and painless, and they may be found on the elbows, knees, or other bony areas.
Urticaria, or hives, can also occur in CSS. These raised, red, itchy welts on the skin are caused by the release of histamine during an allergic or inflammatory reaction. Hives may come and go, and they can be triggered by a variety of factors, including medications, stress, or other allergic reactions.
The gastrointestinal (GI) system can also be affected by Churg-Strauss Syndrome, particularly in the eosinophilic and vasculitic stages of the disease. Inflammation and eosinophil infiltration in the GI tract can lead to symptoms such as:
Abdominal pain is a common symptom in patients with CSS. The pain may be mild or severe, and it is often due to inflammation of the blood vessels that supply the intestines (intestinal vasculitis). Reduced blood flow to the intestines can lead to tissue damage and even bowel ischemia, a condition where parts of the intestine die due to lack of oxygen.
Some patients may experience diarrhea, nausea, or vomiting, while others may develop gastrointestinal bleeding. This can manifest as blood in the stool or vomit, and in severe cases, it may require hospitalization for treatment and blood transfusions.
Churg-Strauss Syndrome can have a significant impact on the nervous system, particularly through peripheral neuropathy. This occurs when inflammation and damage to blood vessels reduce blood flow to the nerves, leading to nerve damage.
Peripheral neuropathy is the most common neurological manifestation of CSS, affecting up to two-thirds of patients. It typically presents as numbness, tingling, weakness, or pain in the hands and feet. The nerve damage may be due to a condition called mononeuritis multiplex, where multiple nerves in different parts of the body are affected. In severe cases, the neuropathy can cause significant muscle weakness or even paralysis.
Although rare, Churg-Strauss Syndrome can also affect the central nervous system (CNS), which includes the brain and spinal cord. CNS involvement may cause strokes, seizures, or changes in mental function, such as confusion or memory problems.
The kidneys are less commonly involved in Churg-Strauss Syndrome than other organs, but when they are affected, it can lead to serious complications. Inflammation of the blood vessels in the kidneys (renal vasculitis) can impair kidney function and lead to glomerulonephritis, a condition that affects the kidney's ability to filter waste from the blood.
Glomerulonephritis in CSS can cause symptoms such as blood in the urine (hematuria) and high levels of protein in the urine (proteinuria). If the inflammation is severe, it can lead to kidney failure, requiring dialysis or even a kidney transplant.
One of the hallmarks of Churg-Strauss Syndrome is its multisystem nature. The disease can affect virtually any organ in the body, and the extent of organ involvement varies greatly between patients. Some may experience mild symptoms limited to the skin and lungs, while others may suffer from widespread organ damage involving the heart, kidneys, and nervous system.
The severity of the disease also fluctuates, with some patients experiencing periods of remission followed by flare-ups of inflammation. This unpredictability makes Churg-Strauss Syndrome challenging to manage, requiring close monitoring and individualized treatment plans.
Because Churg-Strauss Syndrome can affect so many different organs, early diagnosis and treatment are critical to preventing permanent organ damage. Prompt medical attention can reduce the risk of life-threatening complications, such as heart failure, kidney failure, or stroke.
Treatment typically involves corticosteroids to reduce inflammation, along with immunosuppressive drugs to control the immune system. Newer biologic therapies, such as mepolizumab, specifically target eosinophils and have shown promise in managing the disease while minimizing side effects.