This study will evaluate the safety and effectiveness of micellar paclitaxel for treating severe psoriasis. Paclitaxel in another formulation (Taxol) is approved by the Food and Drug Administration for use in patients with cancer. This drug can decrease growth of cancer cells and of new blood vessels. Because patients with psoriasis have an increase in skin cell and blood vessel growth, paclitaxel may also improve their condition. The dose of drug used in this study is much lower than those used to treat cancer patients and is expected to cause relatively few side effects.