Churg-Strauss syndrome

Last edited 05/2020 and last reviewed 09/2022

Churg-Strauss syndrome is a rare condition characterised by asthma and blood eosinophilia together with an eosinophilic vasculitis

Also known as Eosinophilic granulomatosis with polyangiitis (EGPA)

• an annual incidence of 3.1 cases per million (1)

The initial phase of the disorder is one of asthma and allergic rhinitis, often followed by peripheral blood eosinophilia with eosinophilic tissue disease. The vasculitic phase that follows is life-threatening; however, it can often be treated effectively with immunosuppression.

• eosinophil-rich and necrotising granulomatous inflammation often involving the respiratory tract, and necrotising vasculitis predominantly affecting small to medium vessels, and associated with asthma and eosinophilia. ANCA is more frequent when glomerulonephritis is present
• characteristic features of EGPA are asthma (typically late-onset), peripheral blood and tissue eosinophilia, fever, and systemic vasculitis
• asthma especially distinguishes EGPA from granulomatosis with polyangiitis (GPA, previously known as Wegener’s granulomatosis) and microscopic polyangiitis (MPA)
• renal involvement is relatively uncommon.
• asthma is the cardinal feature and precedes systemic features in virtually all cases; onset is late in life and becomes more severe until the onset of vasculitis
  • chest x-ray shows infiltrates in <=77%
• cardiac disease is common (<=47%) and is an important cause of mortality, due to congestive heart failure, pericardial effusion and restrictive cardiomyopathy
• mononeuritis multiplex is a common (70%) feature of EGPA, where it is much more frequent than in GPA and MPA

Management

• induction treatment for most patients with ANCA associated vasculitis (AAV) should be with cyclophosphamide or rituximab and glucocorticoids
• AAV should be considered to be a chronic disease needing longterm immunosuppressive therapy
• rituximab should be considered as an alternative induction agent for those at high risk of infertility and infection
• mortality remains high, and late death is due to cardiovascular disease, infection (secondary to treatment) and malignancy

Reference:

• Davies DJ. Small vessel vasculitis. Cardiovascular Pathology 2005; 14 (6): 335-346.
• ARC Autumn 2012. Topical Reviews - ANCA-associated vasculitis; 1:1-12.
• Yates A, Watts R. ANCA-associated vasculitis. Clinical Medicine 2017 Vol 17, No 1: 60–4