Getting a diagnosis of axial spondyloarthritis is not always straightforward. There are a number of steps rheumatologists need to take to diagnose the condition and understanding those steps will really help you manage the process. 

Dr Aisling Coy, a Consultant Rheumatologist in Salisbury, explains how axial spondyloarthritis, or axial SpA for short, is diagnosed.  

When a rheumatologist diagnoses axial SpA they will use a combination of tests and physical examinations to understand whether or not someone has the condition. However, even for an extremely experienced rheumatologist, making a definitive diagnosis can be a tricky process. It can involve multiple visits and there are likely to be lots of healthcare professionals involved. 

Symptoms

The symptoms that you tell your rheumatologist are so important. Back pain is the most common feature of axial SpA, however symptoms can vary from person to person – making it difficult to immediately recognise the condition. There is no “one key feature” that can indicate a definitive diagnosis of axial SpA. 

Inflammatory symptoms are the most important ones and you’ll be asked about these in your rheumatology appointment. This could include inflammatory back pain, but also problems with your joints and tendons. Psoriasis of the skin, anterior uveitis (red, painful eyes), or gut symptoms could also be important. You may also be asked about other infections, including food poisoning, or sexually transmitted infections.  

Your rheumatologist may also refer you on to other specialists, particularly if you are experiencing gut, eye, or skin problems that can be associated with axial SpA. 

Tests and investigations

You will be given a physical examination that will focus on movements of the spine and the presence or absence of other features that may suggest inflammatory disease.  

Typically your rheumatologist will carry out other investigations, to help them understand whether or not you’ve got axial SpA, but these aren’t conclusive on their own. You may be given a blood test to investigate whether inflammatory markers in your blood are raised. You may also be given a genetic test for a gene called HLA-B27, which is often associated with axial SpA. However, the presence of the gene on its own does not mean you have the condition. And equally, its absence does not mean that you don’t have the condition – there are many individuals with axial SpA who are not positive for HLA-B27.  

Imaging

Imaging can be really useful in the diagnosis of axial SpA. And it is likely that an X-ray of your lumbar spine (lower back) and sacroiliac joints (linking your pelvis and lower spine) will be carried out. An MRI, often using a specific protocol, may also be required if the X-ray results don’t provide a definitive answer.  

Considering a diagnosis of axial SpA can be a complex process. A rheumatologist will use various pieces of a diagnostic jigsaw puzzle. Ultimately, once put together, the pieces of the jigsaw will indicate to either: confirm, watch and wait, or exclude a diagnosis of axial spondyloarthritis. 

Want to know more about the diagnosis process, then check out this blog by Dr Poonam Sharma