Seronegative spondyloarthropathies are a family of joint disorders that classically
include ankylosing spondylitis (AS), psoriatic arthritis (PsA), inflammatory bowel
disease (IBD) associated arthritis, reactive arthritis (formerly Reiter syndrome; ReA),
and undifferentiated SpA. Enthesitis, or inflammation of the sites where the tendons or
ligaments insert into the bone, is a key pathological finding in SpA . It is considered
the hallmark and characteristic feature of spondyloarthritis (SpA). Entheses could be
classified as fibrous entheses and fibrocartilaginous entheses. Regional structural
damage, such as tendon injuries and bone erosions, are frequently caused by persistent
enthesitis. The healing process that follows may result in the emergence of enthesophytes
and, eventually, functional impairment of related anatomic structures. Imaging modalities
for evaluating entheseal lesions include conventional radiology, bone scintigraphy,
magnetic resonance imaging (MRI) and power Doppler (PD) ultrasound (US). US has its own
unique advantage in the diagnosis of enthesitis in AS; it uses a high-frequency or
ultra-high-frequency probe that effectively visualizes the internal structure of the
tendon and is recognized as the gold standard for tendon involvement.
It is superior to clinical examination in the detection of peripheral enthesitis.
Manifestations of tendon enthesitis in SpA on US include a thickened tendon,
hypoechoicity, local calcification and bony erosion. Abnormal blood flow in tendon
entheseal sites can be detected by Power Doppler US. Fibromyalgia (FM) is a syndrome
characterized by chronic musculoskeletal pain. The main symptoms of which are muscle
stiffness, joint stiffness, insomnia, fatigue, mood disorders, cognitive dysfunction,
anxiety, depression, general sensitivity and the inability to carry out normal daily
activities [8, 9]. It can also be associated with specific diseases, such as infections,
diabetes, rheumatic diseases and psychiatric or neurological disorders. Smythe and
Moldofsky later developed the name "fibromyalgia" after identifying "pain points," which
are areas of severe tenderness. These points are defined as areas of
hyperalgesia/allodynia when a pressure of about 4 kg causes pain.