American clinicians investigated a number of cases of juvenile dermatomyositis (JDM) in which symptoms and signs consistent with one of the three forms (axial, peripheral or psoriatic) of ankylosing spondylitis (AS) subsequently developed:
- seven patients met the criteria (clinical and laboratory) for both conditions,
- an average of seven years elapsed between the diagnosis of JDM and that of SpA,
- 20% of the patients tested were positive for the HLA-B27 antigen and a third had a psoriatic component,
- the vast majority of patients responded to SpA-specific therapies.
Although this type of association is rare, this research sheds light on the continuum between two autoimmune conditions with an inflammatory component.
