Spondyloarthropathies in childhood.

The concept of spondyloarthropathies in childhood is emerging. It should now be more easily recognized since more specific diagnostic criteria are available for young patients. It probably accounts for about 20% of the whole group of chronic arthritides seen in paediatric rheumatology clinics. Juvenile ankylosing spondylitis stricto sensu is very rare in childhood. Most children who present with peripheral arthritis at onset meet the diagnostic criteria of undifferentiated spondylo-arthropathies such as those of the SEA syndrome, or those of the ESSG or Amor criteria. At follow-up, quite a large proportion of children may develop axial involvement. Psoriatic arthritis differs from the other spondyloarthropathies with a different sex ratio, and an earlier onset. The role of immunogenetic, environmental and ethnic factors are important for a better understanding of these diseases.