A case of progressive pseudorheumatoid arthropathy of 'childhood' with the diagnosis delayed to the fifth decade

Progressive pseudorheumotoid dysplasia: A presentation of four cases with slow and rapid progression and effects of early rehabilitation program

Progressive pseudorheumotoid dysplasia (PPD) is a rare hereditary musculoskeletal disorder which is usually misdiagnosed due to its clinical resemblance to juvenile idiopathic arthritis. It has a high incidence in the Middle East, Gulf States, and countries of Mediterranean basin. Herein, we present four cases of PPD from Turkey (two siblings pair from the same kindred who are far paternal cousins) showing different disease courses. The progression of disease was particularly aggressive in the male sibling who suffered from severe scoliosis with more crippling joint disease. These four cases of PPD support the clinical heterogeneity and variable expressivity of PPD. In this article, we draw attention to the effects of patient education and early rehabilitation which helped to slow progression of range of motion loss.

Progressive pseudorheumatoid dysplasia: a rare childhood disease

Progressive pseudorheumatoid dysplasia (PPRD) is a genetic bone disorder characterised by the progressive degeneration of articular cartilage that leads to pain, stiffness and joint enlargement. As PPRD is a rare disease, available literature is mainly represented by single case reports and only a few larger case series. Our aim is to review the literature concerning clinical, laboratory and radiological features of PPRD. PPRD is due to a mutation in Wnt1-inducible signalling protein 3 (WISP3) gene, which encodes a signalling factor involved in cartilage homeostasis. The disease onset in childhood and skeletal changes progresses over time leading to significant disability. PPRD is a rare condition that should be suspected if a child develops symmetrical polyarticular involvement without systemic inflammation, knobbly interphalangeal joints of the hands, and gait abnormalities. A full skeletal survey, or at least a lateral radiograph of the spine, can direct towards a correct diagnosis that can be confirmed molecularly. More than 70 WISP3 mutations have so far been reported. Genetic testing should start with the study of genomic DNA extracted from blood leucocytes, but intronic mutations in WISP3 causing splicing aberrations can only be detected by analysing WISP3 mRNA, which can be extracted from cultured skin fibroblasts. A skin biopsy is, therefore, indicated in patients with typical PPRD findings and negative mutation screening of genomic DNA.

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.

Case Details

We report the case of a 15-year-old girl with PPD who was misdiagnosed with JIA.

Conclusion

In conclusion, PPD is a rare SEMD and can be confused with 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.

Progressive Pseudorheumatoid Dysplasia or JIA?

Progressive pseudorheumatoid dysplasia (PPD) or spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA) is a rare arthropathy of childhood involving the axial skeleton as well as small peripheral joints. A 10-year-old boy was referred by a general practitioner with pain and deformity in the fingers of hands and limping gait. There was no joint synovitis although the finger joints were bulky on examination with mild flexion deformity. Patient had exaggerated kyphosis and lumbar lordosis with pigeon chest and restricted hip joint movements. Anteroposterior X-rays of the hip joints revealed widened and flattened epiphyses of the femoral heads with narrow and irregular joint spaces. Hand X-rays revealed periarticular osteopenia, significant narrowing of the joint spaces of proximal interphalangeal, and distal interphalangeal joints, together with osseous enlargement of the basis of metacarpal bones and phalanges. Spinal X-rays revealed generalized platyspondyly and anterior beaking of vertebral bodies. There was a clear mega os trigonum in his feet images. All blood investigations were normal with no evidence of inflammation and thyroid hormone levels were normal. The diagnosis of PPD was favored by imaging studies and normal inflammatory markers and the patient was treated with physiotherapy, family counseling, and anti-inflammatory medications.