The purpose of the study is to evaluate the effectiveness and safety of infliximab (Remicade) in patients with plaque-type psoriasis.

The purpose of this study is to investigate the safety and possible usefulness of infliximab therapy for patients with severe plaque psoriasis. In a previous small study of infliximab in 33 patients with psoriasis, about 80% of patients treated with infliximab showed improvement in their psoriasis symptoms after the first 3 infusions, while 20% of patients who received placebo showed improvement. The patients will receive infusions of infliximab either 3 or 5 mg/kg or placebo at weeks 0,2,6. Patients who have significant psoriasis at week 26 will receive an additional infusion.

Inclusion Criteria:

• Must be 18 years of age or older at time of enrollment
• may be male or female
• Have had a diagnosis of plaque-type psoriasis at least 6 months prior to screening
• Have plaque-type psoriasis covering at least 10% of total BSA at baseline
• Have previously received PUVA and/or other systemic treatment for psoriasis

Exclusion Criteria:

• Have non-plaque forms of psoriasis
• Have a history of drug-induced psoriasis
• Are pregnant, nursing, or planning pregnancy within 12 months of enrollment
• Have had any previous treatment with infliximab or any therapeutic agent