Enthesitis is

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of the

entheses The enthesis (plural entheses) is the connective tissue which attaches tendons or ligaments to a bone. There are two types of entheses: ''Fibrous tissue, fibrous entheses'' and ''fibrocartilaginous entheses''. In a fibrous enthesis, the collage ...

(singular: enthesis), the sites where

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

ligament A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...

s and

joint capsule In anatomy, a joint capsule or articular capsule is an envelope surrounding a synovial joint.bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

s. It is a type of

enthesopathy An enthesopathy refers to a disorder involving the attachment of a tendon or ligament to a bone. This site of attachment is known as the entheses, enthesis (pl. entheses). If the condition is known to be Inflammation, inflammatory, it can more pr ...

, meaning any pathologic condition of the entheses, with or without inflammation. There are some cases of isolated, primary enthesitis which are very poorly studied and understood. It is known to be associated with other

autoimmune disease An autoimmune disease is a condition that results from an anomalous response of the adaptive immune system, wherein it mistakenly targets and attacks healthy, functioning parts of the body as if they were foreign organisms. It is estimated tha ...

s, like spondyloarthropathies and psoriasis (thought to often precede psoriatic arthritis). A common autoimmune enthesitis is at the

heel The heel is the prominence at the posterior end of the foot. It is based on the projection of one bone, the calcaneus or heel bone, behind the articulation of the bones of the lower leg. Structure To distribute the compressive forces exerted ...

, where the

Achilles tendon The Achilles tendon or heel cord, also known as the calcaneal tendon, is a tendon at the back of the lower leg, and is the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcane ...

attaches to the

calcaneus In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel; : calcanei or calcanea) or heel bone is a bone of the Tarsus (skeleton), tarsus of the foot which constitutes the heel. In some other ...

. It is associated with HLA B27 arthropathies, such as

ankylosing spondylitis Ankylosing spondylitis (AS) is a type of arthritis from the disease spectrum of axial spondyloarthritis. It is characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. With AS, eye and bow ...

psoriatic arthritis Psoriatic arthritis (PsA) is a long-term inflammatory arthritis that may occur in some people affected by the autoimmune disease psoriasis. The classic features of psoriatic arthritis include dactylitis (sausage-like swelling of the fingers ...

, and

reactive arthritis Reactive arthritis, previously known as Reiter's syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infect ...

Signs and symptoms

Early clinical manifestations are an aching sensation akin to "working out too much", and it gets better with activity. It is worse in the morning (after sleeping and not moving). The muscle insertion hurts very focally as it joins into the bone, but there is little to no pain at all with passive motion. Symptoms include multiple points of tenderness at the heel, tibial tuberosity,

iliac crest The crest of the ilium (or iliac crest) is the superior border of the wing of ilium and the superolateral margin of the greater pelvis. Structure The iliac crest stretches posteriorly from the anterior superior iliac spine (ASIS) to the posterio ...

, and other tendon insertion sites.

Diagnosis

Management

* Non steroidal anti-inflammatory drugs (NSAIDs). *

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...

injections. * Disease-modifying anti-rheumatic drug (DMARD).

Related conditions

Anatomically close but separate conditions are: *

Apophysitis In the skeleton of humans and other animals, a tubercle, tuberosity or apophysis is a Tubercle, protrusion or eminence that serves as an attachment for skeletal muscles. The muscles attach by tendons, where the enthesis is the connective tissue bet ...

, inflammation of the bony attachment, generally associated with overuse among growing children. * Tendinopathy is a disorder of the tendon, and is associated with direct injury or repetitive activities.

References

External links

{{Soft tissue disorders Rheumatology