Watching out for Enthesitis

What is Enthesitis?

Enthesitis is a condition where the entheses – sites where tendons and ligaments insert and attach onto the bone surface become painful and inflamed. 1 This inflammation is thought to be the result of faulty signaling between cells in the immune system.1

The development of enthesitis has been associated with the presence of HLA B27, a gene strongly linked to Ankylosing Spondylitis (AS).2 The two conditions often occur together, with between 25 and 58% of AS patients also reporting enthesitis.In fact, the link is so strong that enthesitis has been defined as a characteristic feature of AS.2

Where does enthesitis cause pain?

Enthesitis can strike anywhere the bone meets tendon.3 It frequently affects sites commonly associated with AS, for example the pelvis and the lower back. However, enthesitis pain can also be experienced in the periphery – the knees, the heels, (which is the most frequent site) and the soles of the feet.This means that the pain in any of these areas as well as in the lower back could all be warning signs of possible AS.4,5

Enthesitis symptom hotspots3

Spot it early, and tell your doctor

Enthesitis is often underdiagnosed in the clinic.5 It can be tricky for your doctor to spot as the obvious symptoms are not always present and current diagnostic methods lack sensitivity.2 You can help overcome these obstacles by keeping a record of your symptoms with the tracker above.

Fill the tracker in over the course of a month, noting location of pain and the number of days it has appeared then show it to your doctor at your next appointment.  A big-picture view of your symptoms may help your doctor diagnose enthesitis more quickly and precisely. This, in turn, will contribute to a better understanding of your overall disease state and greater likelihood of diagnosing AS.

In terms of how your doctor will diagnose enthesitis, the first step will usually be a physical examination, pressing at the ends of tendons and ligaments to check for pain.6 Ask your doctor to check any areas where you have experienced pain.

Sometimes, lack of apparent swelling or inaccessibility of the site of pain can prevent physical diagnosis.5,6 In this case imaging technologies, such as ultrasound or MRI can be used.2,5,7 These technologies are also more sensitive than physical assessments, if your doctor has not detected enthesitis but you’re still in pain, you may wish to ask them to explore these options to confirm their diagnosis.2,5,7

Ways to feel better

As with many aspects of AS, a diagnosis of enthesitis may take time to confirm. While you wait, there are a number of steps you can take to manage your discomfort. General self-care tips for inflammation will work well – warm baths, insoles and cushioning, ice packs to sooth swollen joints. Evidence from AS patients suggests that massages may also help relieve pain and improve quality of life.8

If you think you or anyone you know may be affected by enthesitis, start keeping a record of your symptoms and talk to a doctor about your options.


This article was written by Dr Shashank Akerkar, with help from the resident experts at A social site helping the whole AS community to: Learn. Share. Inspire. Discuss.


  1. Schett G Enthesitis: from pathophysiology to treatment. Nat Rev Rheumatol. 2017 Nov 21;13(12):731-741
  2. Spadaro A. Clinical and imaging assessment of peripheral enthesitis in ankylosing spondylitis. Int. J. Clin. Rheumatol. (2012) 7(4), 391–396
  3. Kelsall J. What Is the Location of Enthesitis in Ankylosing Spondylitis and Psoriatic Arthritis Patients and How Do They Respond to Anti-TNF Treatment? 2015 ACR/ARHP Meeting, Abstract 2877.
  4. Kataria RK. and Brent LH. Am Fam Physician. 2004; 69: 2853-2860.
  5. Kehl A et al. Enthesitis. New Insights Into Pathogenesis, Diagnostic Modalities, and Treatment.  Arthritis Rheumatol. 2016 February; 68(2): 312–322.
  6. McGonagle D and Benjamin M. Entheses, enthesitis and enthesopathy. Available at: Accessed December 2017.
  7. Zhang H. Ultrasonographic evaluation of enthesitis in patients with ankylosing spondylitis. J Biomed Res. 2017 Jan 19;31(2):162-169.
  8. Chunco, R. Int J Ther Massage Bodywork. 2011; 4: 12–17.