We are doing this research study to evaluate the effectiveness and safety of fluphenazine
decanoate when injected with a needle into psoriasis lesions in adults. Fluphenazine
decanoate is FDA (U.S. Food and Drug Administration) approved for use in people who have
schizophrenia and psychotic symptoms. Fluphenazine decanoate is not approved by the FDA for
use in psoriasis. Fluphenazine decanoate slows T cell growth in cells in laboratory test
tubes. Its usefulness and safety in people with psoriasis will be investigated in this study.