Last reviewed: 25 Sep 2021
Last updated: 14 Nov 2018



History and exam

Key diagnostic factors

  • history of asthma, allergic rhinitis, or sinusitis
  • focal numbness or weakness
  • nasal discharge or stuffiness, or facial pain
  • palpable purpura and petechiae
  • wheeze
  • haemoptysis
  • skin nodules

Other diagnostic factors

  • use of certain medications
  • fatigue, arthralgias, myalgias
  • shortness of breath or cough
  • abdominal pain
  • sensory or motor deficits
  • tachypnoea
  • rales
  • peripheral oedema
  • orthopnoea
  • hepatojugular reflux

Risk factors

  • history of asthma, allergic rhinitis, or sinusitis
  • use of certain medications

Diagnostic investigations

1st investigations to order

  • FBC with differential
  • serum anti-neutrophil cytoplasmic antibodies (ANCA)
  • serum CRP
  • erythrocyte sedimentation rate
  • serum urea and creatinine
  • urinalysis
  • pulmonary function test
  • chest x-ray
  • echocardiogram

Investigations to consider

  • flow cytometry of peripheral blood
  • molecular testing for FIP1L1/PDGFR alpha mutation
  • serum IgE
  • serum-specific IgE and IgG to Aspergillus fumigatus
  • stool culture for ova and parasites
  • Toxocara serology
  • CT chest
  • electromyogram
  • bronchoscopy with bronchoalveolar lavage (BAL)
  • biopsy of affected tissue
  • lower extremity ultrasound
  • CT angiography
  • bone marrow biopsy
  • thiopurine methyltransferase level
  • HIV testing

Treatment algorithm



Karina Keogh, MBBCh

Assistant Professor

Division of Pulmonary and Critical Care Medicine

Mayo Clinic




KK is an author of a number of references cited in this topic and has developed educational material on Churg-Strauss syndrome for First Consult (Elsevier). KK has undertaken contractual research for GlaxoSmithKline (utilizing mepolizumab and sirukumab in asthma trials), but received no personal financial gain for this work.


Dr Karina Keogh would like to gratefully acknowledge Dr Garvan Kane, a previous contributor to this topic. GK is an author of a number of references cited in this topic.

Peer reviewers

Raashid Luqmani, DM, FRCP, FRCP(E)

Professor of Rheumatology

NIHR Musculoskeletal Biomedical Research Unit

Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Science

University of Oxford




RL has organisational financial interests with funds received for consultation and training on disease assessment in vasculitis for GlaxoSmithKline, Nordic, and Chemocentryx. RL has received personal funds for lectures on vasculitis from Roche and Nippon Kayaku. RL is an author of a reference cited in this topic.

Matthew D. Morgan, MB ChB, MRCP, PhD

Clinical Senior Lecturer in Renal Medicine

Centre for Translational Inflammation Research

University of Birmingham Research Laboratories

Queen Elizabeth Hospital Birmingham




MDM has been a paid consultant for Sphere Medical Ltd, and has received research grants and funding from GlaxoSmithKline and Novartis.

Philip Seo, MD, MHS

Assistant Professor of Medicine

Division of Rheumatology

Johns Hopkins University School of Medicine


Johns Hopkins Vasculitis Center




PS declares that he has no competing interests.

Jaap Van Laar, MD, PhD

Professor of Clinical Rheumatology

Institute of Cellular Medicine

Newcastle University

Newcastle upon Tyne

Honorary Consultant Rheumatologist

The James Cook University Hospital




JVL is consultant for Roche, the manufacturer of rituximab, and has received speaker fees and reimbursements for attending several conferences.

Robert A. Ortmann, MD

Associate Professor and Director

Division of Rheumatology

University of Arkansas for Medical Sciences

Little Rock



RAO declares that he has no competing interests.

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