This is a multicenter, prospective, 5-year surveillance study of approximately 5000 Raptiva-treated patients and approximately 500 non Raptiva treated patients (formerly 2500 comparison patients who were treated with a biologic therapy other than Raptiva) with chronic moderate to severe plaque psoriasis who are candidates for treatment with Raptiva.

Inclusion Criteria:

• Have ever had a physician's diagnosis of chronic moderate to severe plaque psoriasis and be a candidate for treatment with Raptiva
• Are being treated with or initiating Raptiva therapy at the time of enrollment
• Be able to provide written informed consent
• Be willing and able to fully to participate for the duration of patient follow-up (5 years)

Exclusion Criterion:

• Have previously received at least one dose of Raptiva and are not currently using or restarting treatment with Raptiva at the time of enrollment

Notes:

If you are a doctor who is interested in participating as a study site, contact the RESPONSE Registry hotline for more information.

If you are an interested patient, contact your dermatologist (or the doctor treating your psoriasis) regarding this study. A list of participating doctors is below. If your doctor is not listed, then he/she can call the RESPONSE Registry Hotline at 1-800-516-1505 for more information.