Assessment of Whole Body Cryotherapy in Treatment of Active Axial Spondylarthritis

Whole body cryotherpy (WBC) is a well-tolerated procedure that implies patients' exposition at a temperature of approximately -110 degrees. A considerable increase in the popularity of WBC has occurred in rheumatologic patients, despite a lack of evidences of its efficiency. Because of its interesting anti-inflammatory properties, the investigators think that WBC could be an alternative treatment to classical NSAIDs (Non Steroidal Anti Inflammatory Drugs) and corticosteroids, in patients suffering from axial spondyloarthritis. This is a proof of concept study.

The treatment arm :Whole body cryotherpy (WBC) (20 sessions of 3 minutes at a temperature of -110 degrees Celsius, on the basis of two sessions a day, spread over two weeks). The control arm : Whole body cryotherpy (WBC) (20 sessions of 1 minute at a temperature of -60 degrees Celsius, on the basis of two sessions a day, spread over two weeks).

assess WBC efficacy on disease activity with Bath Ankylosing Spondylitis Activity Index improvement between baseline and week 2 in patients with active axial spondyloarthritis. a difference of 20 points on BASDAI scale is expected between the experimental arm and the placebo is expected

Inclusion Criteria: patients suffering from axial spondyloarthritis diagnosed according to ASAS criteria, with sacroiliitis on X-rays or MRI, with active disease (BASDAI > 4/10) despite a stable treatment will be included. Exclusion Criteria: contra indication to cooling, previous WBC treatment, no social security cover