Flow cytometry and ELISA analysis revealed the following comparisons between psoriasis patients and healthy volunteers: significant upregulation of lymphocytes (p < 0.05); no significant difference in CD19+ B cells; significant difference in Bregs, CD19+ CD24+ CD38+ cells (p < 0.05); significant difference in memory B cells, CD19+ CD27+ CD38- cells (p < 0.01); significant difference in naive B cells, CD19+ CD27- CD38+ cells (p < 0.05); BAFF, IgD, and IL-4 serum levels were much higher in PsO patients than those in healthy volunteers (p < 0.05). Here, IL4 is linked to psoriasis.