Studies on the prevalence of antiphospholipid antibodies (aPL) in patients with Sneddon's syndrome (SNS) have provided very conflicting results.1-3 Antiphospholipid antibodies, ie, mainly anticardiolipin antibodies (aCL) and/or lupus anticoagulant, were found in 85% of the 41 patients investigated by Kalashnikova et al.1 On the other hand, a study by Zelger et al3 recently reported in the Archives failed to detect aPL in 21 patients with SNS. This discrepancy cannot result from a recruitment bias concerning patients with systemic lupus, since they were excluded in the series described by Kalashnikova et al and absent in the one by Zelger et al.1,3
The following several questions regarding the study by Zelger et al3 are thus prompted: (1) Considering the mention of the aPL antibody syndrome in the differential diagnosis section of their article, can they confirm that the presence of aPL was not an exclusion criterion for