Churg-Strauss syndrome is an inflammatory and allergic lesion of small and medium vessels (capillaries, venules, arterioles), occurring with the formation of necrotizing eosinophilic granulomas. Syndrome is characterized by hypereosinophilia, damage to the bronchopulmonary system, heart, gastrointestinal tract, central and peripheral nervous system, skin and joints. The diagnosis is based on the data of anamnesis, clinical picture, laboratory studies, chest X-ray, lung biopsy. The appointment of systemic glucocorticosteroids and cytostatics is indicated as the main therapy.
Meaning
Churg-Strauss syndrome is a type of systemic vasculitis with granulomatous inflammation of medium– and small-caliber vessels and a predominant lesion of the respiratory tract. Syndrome refers to polysystemic disorders, most often affecting organs with a rich blood supply – skin, lungs, heart, nervous system, gastrointestinal tract, kidneys. Pathology resembles nodular periarteritis in many ways, but unlike it affects not only small and medium-sized arteries, but also capillaries, veins and venules; it is characterized by eosinophilia and granulomatous inflammation, predominant lung damage. In rheumatology, Churg-Strauss syndrome is rare, the annual incidence is 0.42 cases per 100 thousand population. People from 15 to 70 years of age suffer from Churg-Strauss syndrome, the average age of patients is 40-50 years; in women, the disease is detected somewhat more often than in men.
Causes
The causes of Churg-Strauss syndrome are unknown. The pathogenesis is associated with immune inflammation, proliferative-destructive changes and increased permeability of the vascular wall, thrombosis, hemorrhages and ischemia in the area of vascular damage. An important role in the development of Churg-Strauss syndrome is played by an increased titer of antineutrophil cytoplasmic antibodies (ANCA), whose antigenic targets are neutrophil enzymes (mainly proteinase-3 and myeloperoxidase). ANCA cause premature degranulation and disruption of transendothelial migration of activated granulocytes. Vascular changes lead to the appearance of numerous eosinophilic infiltrates in tissues and organs with the formation of necrotizing inflammatory granulomas.
Lung damage comes to the fore with Churg-Strauss syndrome. Histological examination reveals interstitial and perivascular eosinophilic infiltrates in the walls of the pulmonary capillaries, bronchi, bronchioles and alveoli, perivasal and perilymphatic tissues. Infiltrates have a diverse form, usually localized in several segments of the lung, but can spread to the entire pulmonary lobe. In addition to acute-phase inflammatory reactions, cicatricial sclerotic changes in blood vessels and lung tissue are noted.
Viral or bacterial infection (for example, hepatitis B, staphylococcal lesion of the nasopharynx), vaccination, sensitization of the body (allergic diseases, drug intolerance), stress, cooling, insolation, pregnancy and childbirth can provoke the development of Churg-Strauss syndrome.
Symptoms
In its development, the Churg-Strauss syndrome goes through three stages.
The prodromal stage can last several years. In a typical course, the Churg-Strauss syndrome begins with a lesion of the respiratory tract. Allergic rhinitis, symptoms of nasal obstruction, polypous growths of the nasal mucosa, recurrent sinusitis, prolonged bronchitis with an asthmatic component, bronchial asthma appear.
The second stage of the Churg-Strauss syndrome is characterized by an increase in the level of eosinophils in peripheral blood and tissues; it is manifested by severe forms of bronchial asthma with severe coughing attacks and expiratory suffocation, hemoptysis. Bronchospasm attacks are accompanied by severe weakness, prolonged fever, myalgia, weight loss. Chronic eosinophilic infiltration of the lungs can lead to the development of bronchiectatic disease, eosinophilic pneumonia, eosinophilic pleurisy. With the appearance of pleural effusion, chest pains are noted when breathing, increased shortness of breath.
The third stage of Churg-Strauss syndrome is characterized by the development and dominance of signs of systemic vasculitis with multiple organ damage. With the generalization of the Churg-Strauss syndrome, the severity of bronchial asthma decreases. The period between the appearance of symptoms of bronchial asthma and vasculitis is on average 2-3 years (the shorter the interval, the more unfavorable the prognosis of the disease). There is a high eosinophilia (35-85%). The cardiovascular system may develop myocarditis, coronaritis, constrictive pericarditis, mitral and tricuspid valve insufficiency, myocardial infarction, parietal fibroplastic endocarditis Leffler. Damage to the coronary vessels can cause sudden death of patients with Churg-Strauss syndrome.
The damage to the nervous system is characterized by peripheral neuropathy (mononeuropathy, distal polyneuropathy “like gloves or stockings”; radiculopathy, optic nerve neuropathy), central nervous system pathology (hemorrhagic stroke, epileptic seizures, emotional disorders). On the part of the gastrointestinal tract, the development of eosinophilic gastroenteritis (abdominal pain, nausea, vomiting, diarrhea) is noted, less often – bleeding, perforation of the stomach or intestines, peritonitis, intestinal obstruction.
With Churg-Strauss syndrome, polymorphic skin lesions occur in the form of painful hemorrhagic purpura on the lower extremities, subcutaneous nodules, erythema, urticaria and necrotic vesicles. Polyarthralgia and non-progressive migrating arthritis are often observed. Kidney damage is rare, has an unexpressed character, proceeds in the form of segmental glomerulonephritis and is not accompanied by CRF.
Diagnostics
Patients with Churg-Strauss syndrome usually turn to various specialists for primary care – an otolaryngologist, a pulmonologist, an allergist, a neurologist, a cardiologist, a gastroenterologist and get to a rheumatologist late. The diagnosis of Churg-Strauss syndrome is based on clinical and laboratory data and the results of instrumental studies. Diagnostic criteria of the Churg-Strauss syndrome are: hypereosinophilia (>10% of the total number of leukocytes), bronchial asthma, mono- or polyneuropathy, sinusitis, eosinophilic infiltrates in the lungs, extravascular necrotizing granulomas. The presence of at least 4 criteria confirms the diagnosis in 85% of cases.
With Churg-Strauss syndrome, anemia, leukocytosis, increased ESR and the level of total IgE are also detected. More than half of the cases of Churg-Strauss syndrome are characterized by the detection of perinuclear antibodies with antimyeloperoxidase activity (pANCA).
Chest X-ray allows you to detect rapidly disappearing, limited darkening and focal shadows in the lungs, the presence of pleural effusion. A lung biopsy determines granulomatous inflammation of small vessels, infiltrates in the circulatory space containing eosinophils. Differential diagnosis of Churg-Strauss syndrome should be carried out with polyarteritis nodosa, Wegener’s granulomatosis, chronic eosinophilic pneumonia, idiopathic hypereosinophilic syndrome, microscopic polyangiitis.
Treatment
Treatment involves long-term administration of high doses of systemic glucocorticosteroids. As the condition improves, the dose of drugs is reduced. In the presence of lesions of the cardiovascular system, lungs, multiple mononeuritis, it is possible to use pulse therapy with methylprednisolone. When glucocorticosteroids are ineffective, cytostatics (cyclophosphamide, azathioprine, chlorbutin) are used, which contribute to faster remission and reduce the risk of relapses, but create a high risk of infectious complications. Before starting therapy, all medications to which the patient has been sensitized are canceled.
Forecast
Without treatment, the prognosis of Churg-Strauss syndrome is unfavorable. With multiple organ damage, rapid progression of Churg-Strauss syndrome occurs with a high risk of death from cardiopulmonary disorders. With adequate treatment, the 5-year survival rate is 60-80%.