Annular erythema associated with primary Sjögren syndrome: analysis of T cell subsets in cutaneous infiltrates.

Immunohistochemical analysis was performed on the annular erythema associated with Sjögren syndrome. This type of annular erythema is characterized by a doughnutlike appearance with an elevated border and central pallor; it is distinct from subacute cutaneous lupus erythematosus. Histologically this erythema is characterized by coat sleeve-like infiltration of lymphocytes around blood vessels and by nuclear debris in the connective tissue. Vasculitis or epidermal changes suggestive of lupus erythematosus were not observed in any of the cases, although immunoglobulin or complement deposition along the basement membrane zone and focal liquefaction degeneration of the basal layer in involved skin were seen in some cases. Major dermal infiltrates consisted primarily of CD4+ and 4B4+ lymphocytes.