In the USA, the National Psoriasis Foundation of the USA has gathered extensive information to help educate people about these complex diseases, including their appearance, symptoms and medical and social effects. A very professional web site.

Who are they?

"The National Psoriasis Foundation is the world's largest nonprofit organization dedicated to educating, serving and empowering people with psoriasis and psoriatic arthritis.

For more than 35 years, the Psoriasis Foundation has made a significant difference in the way psoriasis and psoriatic arthritis are treated and perceived. We are supported by the donations of more than 52,000 members, and with every new member, our voice grows stronger"