Psoriatic osteoarthropathy and bone scintigraphy

Abstract

Psoriasis is a generalized disease that affects bone as well as skin. Three patterns of bone involvement can be differentiated in psoriatic arthritis distal, central, and distal combined with central. Distal involvement is more specific for psoriatic arthritis, with radial and/or transverse involvement of the distal interphalangeal joints. The progression dynamic and the pattern of distribution are different from those pattern of rheumatoid arthritis: psoriatic arthritis originates in the periarticular bone and extends towards the synovia, whereas in rheumatoid arthritis it extends in the opposite direction. In psoriatic arthritis anterior chest wall syndrome, insertion tendinopathies, and localized or diffuse bone disease are often observed. Bone scintigraphy is more sensitive in the diagnosis of psoriatic bone involvement than clinical examination or conventional radiological imaging, allowing earlier diagnosis through the visualization and documentation of specific patterns and presence of disease in multiple sites. It also allows more discriminating selection of subsequent X-ray examinations to limit radiation exposure. Thus, bone scintigraphy is now the most important diagnostic tool in the assessment of psoriatic arthritis.