Differentiation and Clonality of Lesional Lymphocytes in Small Plaque Parapsoriasis

Abstract

Our findings indicate that small plaque parapsoriasis is a clinically indolent, histopathologically nonspecific, predominantly CD4+ T-cell-mediated disease that, at least in some cases, contains a dominant T-cell clone. These features put small plaque parapsoriasis into a category with certain other members of the parapsoriasis group, namely, pityriasis lichenoides and lymphomatoid papulosis, which have been shown to be clonal T-cell disorders despite their clinically benign course. It remains to be determined if the dominant T-cell clones identified in some cases of small plaque parapsoriasis can ever be the direct precursors of overt cutaneous T-cell lymphomas.