Ankylosing spondylitis (& Atlanto-axial subluxation)
especially in the lower extremities; hip and ankle arthritis;
occasionally, inflammation of the small joints of the feet.
- night pain
- morning stiffness that is relieved
- flattening or loss of lumbar
- Localized tenderness also may be demonstrated at the
insertion of the Achilles tendon
or the plantar fascia.
- Although a history of low back or
buttock pain should be sought, evidence of arthritis of the
sacroiliac joints and spine
may not be apparent for 5 to 10 years
- Extra-articular manifestations of AS are uncommon but include:
- unilateral acute iritis
- aortic valve
- atlantoaxial subluxation
Confirmation of the diagnosis of AS by laboratory studies is difficult
because many results are variable and nonspecific.
- ESR may be normal or
- The platelet count also may
- Rheumatoid factor and antinuclear antibodies are universally
- Results of human leukocyte antigen (HLA) studies are probably the most
diagnostic because HLA-B27 is present
in up to 90% of the AS population.
- Antistreptolysin O antibody titers are not elevated in patients who have
AS. This test may be useful in the diagnosis of rheumatic fever.
The primary goal is to exclude other conditions that can
mimic arthritis, such as
Cabral DA, Malleson PN, Petty RE. Spondyloarthropathies of childhood.
Pediatr Clin North Am. 1995;42:1051-1070
Schaller JG. Juvenile rheumatoid arthritis. Pediatr Rev. 1997;18:337-349