The recent report, “Serum prolactin level in psoriasis”, is very interesting 1. Ghiasi et al. concluded that “it seems that while intracutaneous prolactin may contribute to the pathogenesis of psoriasis, the probable role of pituitary-produced circulating prolactin in the disease process needs further investigation .” There are some concerns on this report. First, although Ghiasi et al. have studied serum prolactin, they based their conclusion on intracutaneous prolactin. The serum prolactin is not the same as intracutaneous prolactin. The serum prolactin can be affected by several physiological and pathological factors. In fertile females, variations of baseline serum prolactin can be expected. Indeed, for psoriasis, there are previous reports on prolactin with controversial results. The difference in baseline pathophysiological conditions of psoriatic patients can be a good explanation for the different findings on prolactin levels in patients.