What is Churg-Strauss syndrome (CSS)?

Churg-Strauss syndrome

Churg-Strauss syndrome is a small vessel multi-system vasculitis characterized by cutaneous vasculitic lesions, eosinophilia (usually < 2.0×109/l), asthma (usually mild), mononeuritis or polyneuropathy and rarely glomerulonephritis (10% cases). Gastrointestinal and cardiac involvements are also recognized.

Clinical features of Churg-Strauss syndrome:

• Pulmonary: Pulmonary findings dominate the clinical presentation with paroxysmal asthma attacks and the presence of fleeting pulmonary infiltrates. Asthma is the cardinal feature and may be present for years before overt features of multi-system vasculitis become apparent.
• Nose: Para-nasal sinusitis or abnormal growths (polyps)
• Cutaneous: Skin lesions include purpura and cutaneous and subcutaneous nodules; occur in up to 70% of patients.
• Nervous: Mononeuritis multiplex occurs in 75% of patients (e.g. ulnar nerve palsy with foot drop) or polyneuropathy. Rarely, it can cause either an anterior or a posterior ischaemic optic neuropathy, which presents with visual loss.
• GIT: Gastrointestinal complications include mesenteric ischemia and gastrointestinal bleeding
• Cardiac: Cardiac involvement is characterized by myo-pericarditis.
• Renal: Glomerulonephritis

Diagnosis of Churg-Strauss syndrome:

• Mostly clinical
• Serum ANCA (MPO subset are elevated but non-specific)
• Biopsy and histopathology: Necrotizing granulomatous vasculitis with extravascular eosinophilic infiltration on lung, renal, or sural biopsy.

Prognosis of Churg-Strauss syndrome:

• Poor, without treatment
• The 5-year survival rate is 25% only
• With treatment, this survival rate may increase to more than 50%
• Death occurs mainly due to myocarditis and MI secondary to coronary arteritis

Treatment of Churg-Strauss syndrome:

• Corticosteroids
• Immunosuppressant drugs (cyclophosphamide, azathioprine, MMF) are necessary for fewer than 20% of patients.
• Pulse steroid IV may be required in major life-threatening organ involvement.

Additional Question:

What are the phases of Churg-Strauss syndrome?

This syndrome passes through 3 phases:

1. The prodromal phase, which may be present for years, and comprises rhinitis, nasal polyposis, and frequent asthma

2. The eosinophilic phase, which can remit and recur for years. It is characterized by the onset of peripheral blood and tissue eosinophilia, resembling Loeffler’s syndrome, chronic eosinophilic pneumonia, or eosinophilic gastroenteritis.

3. The vasculitic phase, which usually occurs in the third or fourth decade of life and is characterized by a life-threatening systemic vasculitis of small and occasionally medium-sized vessels. This phase is associated with constitutional symptoms and signs, fever, and weight loss.

Related question: What are the diagnostic criteria for Churg-Strauss Syndrome?