PUVA is used to treat extensive psoriasis and psoriasis that has not responded to other therapies. PUVA stands for psoralens plus UVA. Psoralens are used orally followed by exposure of lesions to measured amount of a type of ultraviolet light-UVA. Sho term side effects of PUVA therapy include tanning, pruritus, nausea, headache and dizziness. Long term side effects include cataracts, lentigines, photoaging, squamous cell carcinoma and melanoma. Ref: Step by Step(r) Psoriasis Management By Khanna Neena, page 283. Manual of Dermatologic Therapeutics By Kenneth A. Arndt page 262.