Spondyloarthropathy classification

Classification

spondyloarthropathies (SpA) are a group of inflammatory arthritis that consist of ankylosing spondylitis (AS), juvenile onset arthritis, reactive arthritis, non-radiographic ankylosing spondylitis, psoriasis arthritis, and inflammatory bowel disease associated arthritis.

Classification criteria ,that combine different type of information such as imaging, laboratory findings, symptoms, and signs, have been made to describe and define groups for better understanding of clinical and epidemiological studies.

Assessment of spondyloarthritis international society (ASAS criteria) have been widely used to classify the axial spondyloarthritis, which have been described as back pain more than or equal to 3 months and age of onset less than 45 years. ASAS suggest these two sort of criteria:

• Sacroiliitis on imaging plus 1 SpA feature. or
• HLA-B27 plus 2 other SpA features

Sacroiliitis on imaging will be describe as:

• Active inflammation on MRI highly suggested of SpA-assocoated sacroiliitis and/or
• Definite radiograohic sacroiliitis

SpA features:

• Inflammatory back pain
• Arthritis
• Enthesitis
• Anterior uveitis
• Dactylitis
• Psoriasis
• Crohn's disease or ulcerative colitis
• Good response to NSAID
• Family history of SpA
• HLA-B27
• Elevated CRP

Inflammatory back pain has its own criteria to define, which are included:

Inflammatory back pain criteria sets and mnemonic for assessment of spondyloarthritis international society criteria
Calin's criteria for IBP	Berlin criteria for IBP	ASAS IBP criteria mnemonic for criteria "iPAIN"
Age at onset <40 yr	Morning stiffness of >30 min duration	Insidious onset
Duration of back pain >3 months	Improvement in back pain with exercise but not with rest	Pain at night (with improvement upon getting up)
Insidious onset Morning stiffness	Nocturnal awakening (second half of the night only)	Age at onset < 40 yr
Improvement with exercise	Alternating buttock pain	Improvement with exercise
Requires the presence of four of ve criteria	The sensitivity is 70% speci city 81% if two of the four criteria are fulfilled	No improvement with rest The sensitivity is 77.0% and speci city 91.7% if at least four out of ve criteria are fulfilled
IBP: Inflammatory back pain; ASAS: Assessment of spondyloarthritis international society; iPAIN: Inflammatory PAIN

Spectrum of Spondyloarthropathies are included:

• Ankylosing spondylitis
• Axial spondylitis
• Peripheral spondylitis
• spondylitis in general
• Psoriatic arthritis

Modified New York criteria for ankylosing spondylitis
Low back pain for at least 3 mo duration improved by exercise and not received with rest
Limitation of lumbar spine motion in sagittal and frontal planes Chest expansion decreased relative to normal values for age and sex Unilateral sacroiliitis grade 3–4 Bilateral sacroiliitis grade 2–4 Definite ankylosing spondylitis if and any clinical criterion