Ankylosing spondylitis: patient diagnosis and management

Module overview

This module provides an overview of ankylosing spondylitis, including signs and symptoms, diagnosis and management. The module focuses on the difficulties and delays associated with diagnosing this chronic inflammatory disease and developments in diagnostic criteria. Changes in the management of patients with the disease are also discussed, particularly in light of anti-tumour necrosis factor therapy.

Keywords

ankylosing spondylitis, arthritis, chronic conditions, chronic diseases, chronic illnesses, long-term care, long-term conditions, pain, rheumatism, rheumatoid arthritis, rheumatology

Aims

This module discusses the management of patients with ankylosing spondylitis in the context of modern therapy options.

Intended learning outcomes

After reading this module and completing the time out activities you should be able to:

• Describe ankylosing spondylitis, including the signs and symptoms.
• Explore the effect of ankylosing spondylitis on patients’ lives.
• Understand the diagnostic criteria for ankylosing spondylitis and issues surrounding delay in diagnosis.
• Discuss the pharmacological and non-pharmacological treatment of patients with this long-term condition.

• Introduction

  Definition

  Ankylosing spondylitis is a chronic inflammatory disease primarily affecting the spine and sacroiliac joints.
  It is the most common of a group of diseases known as spondyloarthritides, which are rheumatic diseases with common clinical symptoms.

  Incidence

  Ankylosing spondylitis is estimated to affect up to 1% of the general population (Baraliakos et al 2011).

  • Prevalence varies depending on race, with 0.04-0.06% of non-Caucasians affected by the disease compared with 0.1-1.4% of Caucasians (Boonen and van der Heijde 2004).
  • Variation in prevalence is thought to occur because of the presence of the human leucocyte antigen (HLA)-B27 gene within different populations. HLA-B27 is a protein on the surface of white blood cells.
  • The effect of the HLA-B27 gene is unclear (Bowness 2002), but over 90% of people with ankylosing spondylitis have the gene, although only one in 15 people who carry it will develop the disease (Miceli-Richard and Dougados 2004). This suggests that environmental factors such as stress might also influence the development of the condition.
  • Ankylosing spondylitis is more common in men than in women, although the reason for this is unknown. However, estimates vary: Gladman (2003) reported a 9:1 male to female ratio of the disease, Rudwaleit et al (2004) stated that it affects twice as many men as women, and McKenna (2010)suggested a 5:1 male to female ratio of ankylosing spondylitis.
  • The onset of ankylosing spondylitis is typically between 30 and 50 years, although it can occur earlier (Gossec and Dougados 2004).

  • Table 1. Comparison of inflammatory and mechanical back pain

    Inflammatory back pain	Mechanical back pain
    Onset in those under 40 years.	Onset at any age.
    Insidious onset.	More likely to be sudden onset.
    Symptoms improve with exercise.	Symptoms often become worse with exercise.
    No improvement in symptoms with rest.	Symptoms often improve with rest.
    Pain at night, with improvement on getting up.	Pain at night is less likely.
    (Adapted from Sieper et al 2009a, Harris et al 2012)

  

  Like all inflammatory diseases, there are periods of flare and dormancy that make it difficult to distinguish inflammatory back pain from mechanical back pain (Table 1). As a result, there may be a delay in diagnosis of up to ten years (Khan 2003).

  
  

  Features

  • Ankylosing spondylitis causes pain and stiffness in the back, eventually resulting in joint damage and fusion predominantly of the sacroiliac joints, and ankylosing of the vertebrae leading to a classic bamboo spine (Figure 1), although this does not always occur.

  • It can affect the rest of the axial skeleton (shoulders and hips), leading to reduced range of motion and pain.
  • Some individuals with ankylosing spondylitis develop joint destruction and may require total joint replacement, often at a much earlier age than is usual.
  • The disease can also cause peripheral symptoms affecting the knees, hands and feet, which can appear similar to rheumatoid arthritis, with patients experiencing pain and swelling. This can lead to misdiagnoses, thereby delaying appropriate treatment (Khan 2003).

  
  
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  Extra-articular features

  There are several extra-articular (non-skeletal) features that may be associated with ankylosing spondylitis.

  • Acute anterior uveitis affects between 25% and 40% of people with ankylosing spondylitis (Gossec and Dougados 2004).
  • Acute anterior uveitis is characterised by inflammation of the iris, and may be the first indication that a person has ankylosing spondylitis. This condition needs to be treated as an emergency to prevent long-term problems such as glaucoma or reduced vision (Khan 2003).
  • Cardiovascular manifestations such as valve disorders and aortic incompetence may be more common in those who are HLA-B27positive and can worsen with age (Bakland et al 2011).

  Ankylosing spondylitis can have a significant effect on patients’ lives, affecting work, family and social activities, and increasing the risk of depression (National Ankylosing Spondylitis Society (NASS) 2010a). Therefore, early disease management is essential to prevent damage and disability. In a survey of people with ankylosing spondylitis, 72% of respondents were in employment, however only 38% of these individuals received advice or help on coping with symptoms of the condition while at work (NASS 2010b). Pain, fatigue and physical limitations were identified as the 
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• sfactors affecting a person’s ability to work.