Relative risk vs. absolute risk
So, what is important to consider from the study moving forward? The study points out, "the excess risk of lymphoma attributed to psoriasis was 7.9/100,000 psoriasis patients per year. Although patients with psoriasis have an increased relative risk of lymphoma, the absolute risk attributable to psoriasis is low, given that lymphoma is a rare disease and the magnitude of the association is modest."
However, if you do have severe psoriasis, you should remain on the lookout for non-Hodgkin lymphoma, especially cutaneous T-cell lymphoma. Be sure to talk to your doctor about your risk and be diligent in assessing potential symptoms.