Progressive Pseudorheumatoid Dysplasia Misdiagnosed as Seronegative Juvenile Idiopathic Arthritis

BACKGROUND: Progressive pseudorheumatoid dysplasia (PPD) is a rare spondylo-epi-metaphyseal dysplasia (SEMD). It can be confused with juvenile idiopathic arthritis (JIA), both clinically and radiologically. Early detection and diagnosis of PPD are important in helping to relieve the pain and disability associated with this disease and in avoiding unnecessary investigations and anti-rheumatic interventions