Background Progressive pseudorheumatoid dysplasia is an inherited skeletal dysplasia with radiographic changes notably in the spine, similar to spondyloepiphyseal dysplasia tarda. There is also articular cartilage involvement which gives it some clinical resemblance to juvenile rheumatoid arthritis.

Results We report a case of fifteen year old patient presenting chronic painless swollen joints, accompanied by progressive motion restriction and progressive walking difficulties. Radiologically, there was enlargement of the epimetaphyseal portions of the large joints, metacarpal heads, and phalanges, and platyspondyly with irregular delineation of the endplates of the vertebral bodies. Normal values were found for the erythrocyte sedimentation rate and C-reactive protein level. Rheumatoid factors and antinuclear antibodies were negative. The combination of the dysplastic abnormalities of the joints and the spine, the absence of destructive lesions of rheumatoid arthritis and the negativity of inflammatory and immunologic tests led to the diagnosis of progressive pseudorheumatoid dysplasia.

Conclusions Progressive pseudorheumatoid dysplasia is an autosomal recessive disease characterized by abnormal cartilage homeostasis. It should be included among the differential diagnoses of juvenile idiopathic arthritis.

Disclosure of Interest None Declared