Churg-Strauss Syndrome

Indications for Testing

Asthma and presence of systemic disease

Criteria for Diagnosis

American College of Rheumatology, 1990 – ACR criteria for the classification of Churg-Strauss syndrome (4 of 6 required)
- Asthma
- Eosinophilia >10% on differential
- Mono- or polyneuropathy attributable to systemic vasculitis
- Migratory or transient pulmonary infiltrates
- Paranasal sinus disease
- Extravascular eosinophils on biopsy of vascular tissue

Laboratory Testing

Nonspecific
- CBC – eosinophilia on differential
- Urinalysis – may show hematuria
- ESR – elevated
ANCA – 75% have pANCA with MPO+ (rarely PR3 is positive)

Histology

Tissue biopsy of involved organ site – confirm presences of small-to-medium sized artery vasculitis, necrotizing granulomas and eosinophilic infiltration of arterial and venous walls

Imaging Studies

Chest radiograph – frequently will observe infiltrates; pleural effusion in 10%

Prognosis

Relapses are common, especially if maintenance treatments are fully withdraw
Flare-ups might follow reductions of corticosteroid doses

Differential Diagnosis

Wegener granulomatosis
Parasitic infection
- Toxocara spp
- Schistosoma spp
- Trichinella spiralis
- Strongyloides stercoralis
- Wuchereria bancrofti
- Paragonimus westermani
Bronchopulmonary aspergillosis
Hypersensitivity pneumonitis
Hypereosinophilic syndrome

Churg-Strauss syndrome, also known as allergic angiitis granulomatosis, is distinguishable from other pulmonary eosinophilic syndromes by the presence of eosinophilic vasculitis in the setting of asthma and the involvement of multiple end organs (eg, lungs, heart, gastrointestinal tract, nervous system).

Epidemiology

Incidence – 1-3/1,000,000 in U.S.; in asthma patients, may be as high as 67/1,000,000
Age – 40-50 years
Sex – M>F

Pathophysiology

Small vessel vasculitis/angiitis typically necrotizing and involving both arteries and veins
Extravascular necrotizing granulomas and eosinophilic infiltration

Clinical Presentation

Phases of disease
- Prodromal phase
  - Characterized by asthma and allergic rhinitis
  - Typically occurs when individual is 20-30 years and typically persists for many years
- Eosinophilic infiltrative phase
  - Peripheral eosinophilia, eosinophilic tissue infiltration of various organs including the lungs and GI
- Vasculitis phase
  - Constitutional presentation – fever, fatigue, malaise, weight loss
  - Cardiovascular – eosinophilic myocarditis, congestive heart failure
  - Neurologic – peripheral neuropathy (typically mononeuritis multiplex), polyneuropathy, confusion, seizures, cranial nerve palsies, coma
  - Dermatologic – nodules, papules, petechial rash
  - Gastrointestinal – abdominal pain, nausea, emesis, diarrhea
  - Renal – necrotizing glomerulonephritis
  - Ophthalmologic – uveitis, retinopathy
  - Otorhinologic – paranasal sinus disease