Enthesitis is inflammation

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 of the entheses, the sites where tendons or ligaments insert into the bone. It is also called enthesopathy, or any pathologic

Pathology (disambiguation)

Pathology and -logia, study of) is a medical field specializing in the categorization of diseases. Pathological is the adjective form of the term.Pathology may also refer to:- In science :...

 condition involving the entheses. The entheses are any point of attachment of skeletal muscle

Skeletal muscle

Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...

s to the bone

Bone

Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...

, where recurring stress or inflammatory autoimmune disease

Autoimmune disease

Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...

 can cause inflammation

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 or occasionally fibrosis

Fibrosis

Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...

 and calcification

Calcification

Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...

. One of the primary entheses involved in inflammatory autoimmune disease is at the heel

Heel

In human anatomy, 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.- Human anatomy :...

, particularly the Achilles tendon.

It is associated with HLA B27 arthropathies like ankylosing spondylitis

Ankylosing spondylitis

Ankylosing spondylitis , previously known as Bekhterev's disease, Bekhterev syndrome, and Marie-Strümpell disease is a chronic inflammatory disease of the axial skeleton with variable involvement of peripheral joints and nonarticular structures...

, psoriatic arthritis

Psoriatic arthritis

Psoriatic arthritis is a type of inflammatory arthritis that, according to the National Psoriasis Foundation, will develop in up to 30 percent of people who have the chronic skin condition psoriasis...

, and reactive arthritis

Reactive arthritis

Reactive arthritis , is classified as an autoimmune condition that develops in response to an infection in another part of the body. Coming into contact with bacteria and developing an infection can trigger the disease. Reiter's syndrome has symptoms similar to various other conditions collectively...

 (Reiter's syndrome).

Symptoms include multiple points of tenderness at the heel, tibial tuberosity, iliac crest

Iliac crest

-External links: - "Superficial muscles of the gluteal region and posterior thigh." - "Anterior Abdominal Wall: Osteology and Surface Anatomy " - "The Back, Posterior View" * *...

, and other tendon insertion sites.