Spongiotic annular erythema in SS-A/SS-B antibody negative Sjögren's syndrome

We reported four cases of Sjögren's syndrome (SjS) who manifested a new type of annular erythema that differs from the previously described annular erythema seen in anti-SS-A/SS-B antibody positive SjS in both clinical and histological findings. Characteristic histological features are the presence of spongiotic changes around the acrosyringium and perivascular lymphocytic infiltration without liquefaction degeneration or epidermal change, suggesting lupus erythematosus. No complement or immunoglobulin depositions are demonstrated along the basement membrane zone or around blood vessels. Clinically, this type of erythema usually appears on the trunk or extremities with itchy sensations, especially in summer, which contrasts with the preferential occurrence of the previously reported SjS related annular erythema on the facial skin in winter. Immunologically, all four cases lacked anti-SS-A and anti-SS-B antibodies, but possessed positive anti-microsome antibodies or thyroid tests. In three cases, metal allergy was demonstrated by patch test, which might suggest that the sweat duct is the primary target of excreted metals in this condition and that underlying SjS might play some role in the higher prevalence of metal allergy or in induction of sweat duct injury, similar to the interstitial nephritis which is now thought to be an exocrine manifestation of SjS.