Background: Macular atrophy or anetoderma is a rare skin disease of unknown pathogenesis, characterised by wrinkled or flaccid skin.
Objective: The finding of anetoderma in 5 patients followed up because of false-positive seroreactions of syphilis prompted us to study the occurrence of antiphospholipid (aPL) antibodies in anetoderma.
Methods: 14 unselected patients with primary anetoderma (PA) were collected from hospital records and clinical, immunological and histological findings were compared in the two patient groups.
Results: Of the 5 patients, 3 fulfilled the criteria for antiphospholipid syndrome. In two cases, it was secondary to systemic lupus erythematosus (SLE). Of the 14 PA patients 1 had aPL antibodies and 4 had borrelia antibodies. Two patients had thyroid antibodies; 1 of them developed SLE. In several biopsy specimens, microthromboses were seen in both patient groups.
Conclusion: On the basis of this study and our previous findings, it seems that anetoderma is more often associated with aPL-positive SLE or lupus-like disease than with aPL-negative disease. Immunological mechanisms play an important role in both primary and secondary anetoderma. The meaning of false-positive serological tests for syphilis or borrelia and aPL antibodies is not clear, but they may be reacting to some still unidentified antigen. Probably, various systemic as well as local inflammatory and non-inflammatory processes, e.g. microthromboses, can trigger anetoderma via still unknown pathomechanisms.