[Study of carcinoembryonic antigen (CEA) in the epidermis of psoriasis vulgaris].

By immunohistochemical methods, we detected CEA in the epidermis of psoriatic skin in 10 out of 20 cases with the plaque type of psoriasis vulgaris. The CEA detected in the psoriatic skin was limited in area to the intra-squamous cell cytoplasm, cell membranes, and intercellular space just beneath the markedly parakeratotic layer. It was not found in the orthokeratotic layer. At the same time, serum CEA value was measured in 7 cases. No increased CEA value was found in any case with or without positive CEA in the epidermis. The origin of CEA in the psoriatic skin might be: 1) squamous cell just below the rapidly proliferating parakeratotic cells. 2) CEA contained in eccrine sweat and deposited by dishidotic procedure. It can not involve permeation of CEA in serum into the epidermis. Of the 1) and 2) theories we prefer the first, but further study is needed. This is the first report of the existence of CEA in the psoriatic epidermis.