Churg-Strauss Syndrome

Rare: 2–5 new cases/million/y

Average age of onset: 35–50 y

Male = female

Necrotizing eosinophilic vasculitis involving respiratory (100% of pts), cardiac (30–60% of pts), neurologic, GI, renal, and integumentary systems

Respiratory complications from severe asthma exacerbations

CV collapse from coronary artery vasculitis, myocarditis, or cardiac tamponade; represents the major cause of mortality

Peripheral and central neurologic defects (mononeuritis multiplex and cerebral infarcts)

GI vasculitis (abdominal pain and bleeding)

Effects of the standard treatments (steroids and immunosuppressants)

Syndrome includes (1) a history of late-onset asthma, (2) eosinophilia, and (3) systemic vasculitis in two or more organ systems.

Most pts have generalized symptoms, but respiratory effects such as asthma and pulmonary infiltrates are a core clinical feature.

Affects all major organ systems to varying degrees.

Delayed diagnosis is common because the first manifestation is usually synonymous with asthma and allergic rhinitis.

Diagnosis should be considered in pts with asthma and an increased blood eosinophil count or pulmonary infiltrates.

Prognosis: Remission can be obtained in >80% of pts, but relapse does occur.

5-y survival is 80%.

Asthmatic symptoms usually persist despite recovery from vasculitic symptoms requiring chronic steroid use.

Attributed to an immune reaction to inhaled allergens, but the cause is unknown.

Possible link to leukotriene receptors antagonist use.

Three successive phases: (1) asthma and allergic manifestations → (2) blood eosinophil and tissue eosinophil infiltration → (3) systemic phase with subsequent necrotizing vasculitis.

Clinical features tend to divide into two phenotypes: A vasculitic type with manifestations caused by small-vessel vasculitis (purpura, mononeuritis, and renal), and an eosinophilic type, where organ damage is a result of eosinophil infiltration (pulmonary and cardiac involvement). ANCA-positive pts tend to have the vasculitic type.