Immunohistochemical study of elevated expression of squamous cell carcinoma (SCC)-related antigens in erythrodermic epidermis.

Using immunohistochemical staining with the monoclonal antibodies (mAb) of squamous cell carcinoma-related antigens (SCC-RAg), the expression of SCC-RAg in erythrodermic epidermis, which included senile erythroderma following eczema, atopic erythroderma, psoriatic erythroderma, and Sézary syndrome was examined. In senile erythroderma and atopic dermatitis, the most intense staining with SCC-RAg mAb was evident in the upper epidermis. The cytoplasm of epidermal cells showed particularly strong staining. Although serum SCC-RAg in the Sézary syndrome was not as high as in other erythroderma patients, staining with SCC-RAg mAb was relatively strong in the upper epidermis. However, in psoriatic erythroderma cases with severe skin conditions, staining was weakly positive and diffuse throughout the entire epidermis. Following treatment, SCC-RAg decreased significantly with remission. Elevated SCC-RAg release may be attributed to epidermal cells, and SCC-RAg should prove useful as a clinical marker of erythroderma.