Enthesitis

An enthesis is the place where a tendon or ligament is rooted in the bone, and it is made to take load over and over. Enthesitis is what happens when that junction becomes inflamed, and there are two broad ways to get there. Mechanical strain causes isolated enthesitis: too much use, training stepped up too fast, or one spot loaded again and again. Inflammatory enthesitis comes from the body's own immune system, and it is one of the defining signs of the spondyloarthritis family. That family includes psoriatic arthritis, axial spondyloarthritis, reactive arthritis and enteropathic arthritis. The inflammatory kind is likelier when you or a relative has had one of these conditions, when you have psoriasis or inflammatory bowel disease, and in people who have the HLA-B27 gene.

A few closely related words are easily mixed up:

• An enthesis is a tendon's or ligament's anchor in the bone.
• Enthesopathy covers any disorder of an enthesis, whatever its cause. A scan or X-ray report that mentions enthesopathy, or enthesopathic change, means only that something has changed at these attachment points, whether from inflammation, from wear or from years of mechanical strain.
• Enthesitis is narrower: an enthesopathy in which the enthesis is inflamed. It is the kind that goes with inflammatory arthritis, and ultrasound is particularly good at confirming it.

The symptoms sit at the attachment points themselves. You may notice:

• A sore, tender spot at a tendon's or ligament's anchor point, such as the back of the heel
• Soreness that is often at its worst after rest and when you first start moving
• At times, swelling over the sore spot
• Trouble in other joints or the back too, when an inflammatory arthritis is the cause

How the symptoms behave and what the examination finds can identify enthesitis. An important part of the assessment is then to tell an isolated problem from overuse apart from one that belongs to an inflammatory arthritis, since each is handled differently.

Ultrasound is especially useful in enthesitis. The scan lets the attachment points be seen in fine detail and can confirm they are inflamed, even at an early stage, and that in turn helps to settle whether an inflammatory arthritis is present. Point-of-care ultrasound is part of the consultation with Dr Borukhson, and the painful attachment can often be scanned there and then. The ultrasound clinic page tells you more.

Isolated enthesitis is often treated with a change in activity, a planned exercise programme and pain relief. If an inflammatory arthritis is behind it, the treatment centres on that arthritis. Should one site refuse to settle, a carefully weighed ultrasound-guided injection may sometimes help. You and Dr Borukhson settle the plan together.

In enthesitis-related arthritis (ERA), enthesitis and inflamed joints come together as the defining features of a recognised form of inflammatory arthritis. ERA is one of the kinds of juvenile idiopathic arthritis: it starts in childhood or the teens and sits within the wider spondyloarthritis family. It often goes with the HLA-B27 gene and with related conditions among parents, brothers, sisters or other relatives.

A question that sometimes comes up is what happens to ERA in adulthood. Once they are adults, people who had ERA as children are generally looked after as part of the adult spondyloarthritis family, and so are adults who have the same mix of enthesitis and arthritis. The overlap is with axial spondyloarthritis and psoriatic arthritis. The approach does not change: confirm the pattern, look for enthesitis with ultrasound, and treat the inflammatory condition underneath.

Day to day, the goal is to calm the sore attachment point while keeping the area from stiffening. Relative rest works better than complete rest: cut back on whatever sets it off rather than stopping everything. These tend to make a difference:

• Increase the load gradually, with a planned programme of stretching and strengthening instead of sudden bursts
• Wear supportive shoes, and think about a heel pad or insole for pain at the back of the heel or under it, much as for plantar fasciitis
• Keep your weight healthy and stay active in ways that are gentle on the joints, such as swimming or cycling
• If you smoke, giving up is worthwhile, because smokers with spondyloarthritis tend to fare worse

Over a period of weeks to months, isolated enthesitis often eases. Enthesitis that belongs to an inflammatory arthritis generally does well once the arthritis is under good control.

Few cases of enthesitis call for 999 or A&E, and most can wait for a routine appointment; the exceptions are in the lists below, and the paragraph that follows them names the signs for a GP within days.

Treat any of these as a 999 or A&E emergency: call 999 and do not drive yourself to A&E.

• Severe illness with suspected sepsis: a high fever with shaking, confusion, rapid breathing, or feeling dramatically worse over hours
• With a fever or feeling unwell, a rash that does not fade when you press it, a stiff neck with eyes that cannot bear bright light, or skin, lips or tongue turning blue, grey, pale or blotchy, since these can be signs of meningitis or sepsis, as can a very bad headache, confusion or a first seizure with a fever or feeling unwell; on black or brown skin the rash and the change of colour may be easier to see on the palms of the hands or the soles of the feet
• A joint you cannot put weight on or move, or that has moved out of place, or, after a fall or injury, very bad pain or any tingling or numbness
• Chest pain that is crushing, tight or like a pressure, that spreads to an arm, the jaw, the neck, the stomach or the back, that comes with breathlessness, sweating, feeling sick or feeling light-headed, or that came on suddenly and does not go away
• Lips, mouth, throat or tongue that suddenly swell, a throat that feels tight, very fast breathing or a struggle to breathe or to swallow, skin, tongue or lips turning blue, grey or pale (on black or brown skin this may be easier to see on the palms of the hands or the soles of the feet), becoming suddenly very confused, drowsy or dizzy, or fainting and not being able to be woken, since this can be a severe allergic reaction, anaphylaxis, which can follow a dose of any medicine
• An eye that suddenly and completely loses its sight

Any of these needs an assessment that is urgent, on the same day, from your GP or NHS 111:

• A joint that is hot and swollen, with a fever or feeling unwell, since an infected joint has to be ruled out at once, at A&E or through NHS 111
• A joint that has become hot and very swollen suddenly, or is worsening quickly, even without a fever, since an infected joint does not always announce itself with one
• Joint pain with a fever, or feeling hot, cold or shivery, or generally unwell, since an infection in or around a joint has to be found the same day
• A hot, red, swollen tendon attachment, with a fever or feeling generally unwell, since an infection there has to be ruled out at once, at A&E or through NHS 111
• A fever, or feeling generally unwell, on immunosuppressant, biologic or steroid treatment, since an infection has to be treated early; if you are under a rheumatology team, ring them first
• Sudden, severe pain at a tendon, or a snap or pop, since the tendon may have torn rather than simply become inflamed; NHS 111 can say where you should go, and a limb that will take no weight, a joint that cannot be moved, or tingling or numbness after the injury belongs in the first list
• A new red, painful eye, or sight that has blurred, dimmed or changed, which needs an eye casualty or urgent eye clinic the same day, as does an eye that light hurts, since the inflammatory conditions that enthesitis can be part of can affect the eye too; see our uveitis guide
• Being near someone with measles, chickenpox or shingles, while you take a medicine that weakens the immune system, since measles and chickenpox can be dangerous when the immune system is weakened, and you can catch chickenpox from someone with shingles if you have never had chickenpox; NHS 111 can tell you what to do that day

Stiffness lasting beyond the first half hour of the morning, back pain that gets better when you move, a newly swollen joint that is not hot, a finger or toe that has swollen, at a joint or along its whole length, or a new skin rash, alongside pain where a tendon meets the bone, is for a GP within days, since an inflammatory arthritis can begin this way and is best caught early. Pain at an attachment point that lasts beyond a few weeks in spite of rest, or keeps coming back, deserves a routine appointment with your GP or a specialist instead of a long wait. If you are under a rheumatology team for the arthritis behind the enthesitis, a flare that will not settle is one for that team. Where the spine is affected too, the back's warning signs are set out in the seek-help section of our axial spondyloarthritis guide. If you cannot tell how urgent something is, asking is never a mistake.

Because enthesitis is sometimes how an inflammatory arthritis first shows itself, a proper assessment matters, both to settle the pain and to find any wider condition early. If a spot where a tendon meets the bone stays painful, a heel that will not settle for instance, a specialist review, through your GP or booked directly and with ultrasound where it helps, can make sense of it.

How can a sore attachment point be shown to be enthesitis?

How the symptoms behave and a close look at the tender attachment points often point to it. Ultrasound helps a great deal, since it shows these points in close detail, can confirm inflammation and can pick it up early. Point-of-care ultrasound is part of the consultation with Dr Borukhson, so the sore spot can usually be scanned during your visit.

What does enthesopathy on my scan report mean?

It is a catch-all word for any change at an enthesis, where a tendon or ligament meets the bone. On its own it does not say whether the change comes from inflammation, from wear or from years of mechanical strain. Enthesitis is the inflammatory kind in particular, and a specialist review, with ultrasound where it helps, can work out which one a report means.

Is enthesitis serious, or will it get better by itself?

Enthesitis that comes from overuse alone often settles with a change in activity, a planned exercise programme and pain relief. The reason for a proper assessment is that enthesitis now and then turns out to signal an inflammatory arthritis, which is worth finding early. Pain that keeps going where a tendon joins the bone, a heel that stays sore for instance, is worth showing to your GP or a specialist rather than simply waiting for it to pass.

Is an operation or an injection likely?

Most enthesitis is treated without an operation. The usual starting point is to change what you do, exercise and take pain relief, and if an inflammatory arthritis is causing it, treating that condition is what matters most. An ultrasound-guided injection, given after careful thought, may sometimes settle a spot that stays sore, and any plan is one you agree to.