Enthesitis of the hands in psoriatic arthritis: an ultrasonographic perspective.

Psoriatic arthritis is a systemic inflammatory disease in which enthesitis and dactylitis are two of the main hallmarks of the disease. In the last years, ultrasonography is increasingly playing a key role in the diagnosis of psoriatic arthritis and ultrasonography of the entheses, particularly of the lower limbs, is commonly used to assess patients with that disease. New advancements in ultrasound equipment using high frequencies probes allowed us also to identify and characterize the involvementof the entheses of the hand in psoriatic arthritis, confirming the results of the experimental models of the disease and the theory of the sinovial-entheseal complex, even in small joints.