The spondyloarthritis (SpA) involve a group of closely related diseases with common, genetic, clinical and radiologic features. HLA-B27 (+) is a genetic hallmark common to most of patients diagnosed of SpA, although, HLA-B27 (-) people may also suffer from these diseases.
Suggestive clinical features may vary from one disease to another but essentially include: lumbar or dorsal pain during de night, morning stiffness, asymmetrical inflammation of limb joints (predominantly lower limbs), finger inflammation or “sausage digit”, eye inflammation (uveitis) or inflammation of the site where the tendons or ligaments attach to the bone (enthesitis).
Common radiological features include sacroiliitis or enthesopathy. The SpA comprise different disease subtypes: Ankylosing Spondylitis (AS), reactive arthritis, arthritis/spondylitis associated with psoriasis (PsA), arthritis/spondylitis associated with inflammatory bowel disease and undifferentiated SpA.