To recognize their dedication in caring for people with psoriasis – a chronic, genetic disease of the immune system that appears on the skin that affects as many as 7.5 million Americans – the National Psoriasis Foundation named doctors April Armstrong, Ronald Prussick and Jashin Wu to its medical board. It has also reappointed doctor John Koo to the medical board. These dermatologists join the board’s 20 other psoriasis and psoriatic arthritis experts who provide leadership and guidance to the Psoriasis Foundation on medical issues.