It sounds like you have tried a wide variety of treatments for your psoriasis
without complete success. If you have not tried ultraviolet therapy yet, then you should talk to your dermatologist
about the possibility of using this treatment modality. Psoralen is used as either a topical or oral medication in combination with ultraviolet light; the combination is thought to inhibit the rapid growth of cells in psoriatic plaques as the light activates the psoralen. This often correlates with the fact that many psoriasis patients have more controlled disease during the summer months when they are exposed to more sun.
Other systemic therapies that you should inquire about include immunosuppressant medications such as methotrexate and cyclosporine. In the event that you have already tried such potent medications (as well as biologic agents such as Humira), you should talk to your dermatologist about other options. He/she may be able to write a letter of necessity to your insurance company to cover other medications, or may know of some clinical trials with other experimental agents in which you can be enrolled.