Recurrent annular erythema in a case of seronegative Sjögren's syndrome

We describe a case of Sjögren's syndrome who repeatedly developed annular erythema on her extremities. Her anti-nuclear antibody, anti-SSA/Ro antibody, and anti-SSB/La antibody were all negative. Characteristics of the annular erythema included a tendency to appear on the extremities especially in summer, spontaneous regression after 1-2 weeks, and residual slight pigmentation. The histological findings revealed dermal perivascular lymphocytic infiltration admixed with some neutrophils. Slight exsudative changes were found in the upper dermis. There were no epidermal changes. This case suggests the existence of annular erythema which may not be related to the anti-SSA/Ro or anti-SSB/La antibody. Unknown factors other than those antibodies may be involved in the pathogenesis of the annular erythema.