Last reviewed: 28 Aug 2021
Last updated: 23 Feb 2021

Summary

Definition

History and exam

Key diagnostic factors

  • HLA-B27 positive
  • inflammatory back pain
  • iritis/uveitis
  • enthesitis
  • presentation in late teens and early 20s
  • male sex
  • positive family history of AS

Other diagnostic factors

  • fatigue
  • sleep disturbance
  • tenderness at sacroiliac joint
  • dyspnea
  • loss of lumbar lordosis
  • peripheral joint involvement
  • kyphosis
  • psoriasis
  • symptoms of inflammatory bowel disease

Risk factors

  • HLA-B27
  • endoplasmic reticulum aminopeptidase 1 (ERAP1) and interleukin-23 receptor (IL23R) genes
  • positive family history of AS
  • male sex
  • Klebsiella pneumoniae

Diagnostic investigations

Investigations to consider

  • HLA-B27
  • MRI
  • cervical spine x-ray (lateral)
  • lumbar spine x-ray (lateral)
  • thoracic spine x-ray (lateral)
  • ultrasound

Treatment algorithm

Contributors

Authors

Antoni Chan, MBChB, FRCP, PhD

Consultant

Rheumatology Department

Royal Berkshire NHS Foundation Trust

Reading

UK

Disclosures

AC has served on the advisory boards for MSD, Novartis, and Sanofi; contributed to educational events for Janssen, MSD, Novartis, Sanofi, and Celgene; been on the speaker bureau for Janssen, Pfizer, and Novartis; and received travel grants from AbbVie, UCB, Lilly, and Pfizer to attend educational conferences.

Sarah Sacks, MBBS, BSc

Specialist Registrar in Rheumatology

Stoke Mandeville Hospital

Aylesbury

UK

Disclosures

SS declares that she has no competing interests.

Acknowledgements

Dr Antoni Chan and Dr Sarah Sacks would like to gratefully acknowledge Dr Jessica Gunn, Dr Sarah Keidel, Dr Millicent Stone, Dr Raj Sengupta, Dr Athimalaipet V. Ramanan, and Dr Emma Pomeroy, the previous contributors to this topic.

Disclosures

JG, SK, RS, and AVR declare that they have no competing interests. MS is an author of several references cited in this topic. EP is an author of a reference cited in this topic.

Peer reviewers

Roger Sturrock, MD, FRCP

Professor of Rheumatology

Centre for Rheumatic Diseases

University Department of Medicine

Glasgow Royal Infirmary University Trust

Glasgow

UK

Disclosures

RS is an author of a reference cited in this topic.

Andrew Keat, MBBS

Consultant Physician and Rheumatologist

Northwick Park Hospital

Harrow

UK

Disclosures

AK declares that he has no competing interests.

Karl Gaffney, BCh, BAO (Hons), FRCPI, FRCP

Consultant

Norfolk and Norwich University Hospital

Norwich and the Cromer & District Hospital

Cromer

UK

Disclosures

KG is an author of a reference cited in this topic.

Alexios G. Carayannopoulos, DO, MPH

Interventional Spine Physiatrist

Pain Medicine Specialist

Medical Director

Spine Center

Lahey Clinic

Burlington

MA

Disclosures

AGC declares that he has no competing interests.

Use of this content is subject to our disclaimer