Angiogenesis in psoriasis and psoriatic arthritis: clues to disease pathogenesis.

Psoriasis is a common chronic dermatosis occurring in 2% of the population and associated with an inflammatory arthritis--psoriatic arthritis (PsA)--in up to 40% of cases. PsA accounts for approximately 15% of patients attending early synovitis clinics, therefore it represents the second most common diagnostic category after rheumatoid arthritis. There are a number of common pathogenic features that link the skin and the joint inflammatory processes. Angiogenesis appears to be a fundamental inflammatory response early in the pathogenesis and significant abnormalities of vascular morphology and angiogenic growth factors have been described in psoriasis and PsA. This paper will explore the recent published evidence to support the hypothesis that dysregulated angiogenesis provides a primary pathogenic mechanism in psoriasis skin and in the PsA joint.