Small erythematous or cyanotic lesions on the hands and feet of four patients with antiphospholipid antibodies are described. These discrete lesions outline capillaries and do not disappear when pressure is applied. The histologic features are identical to those described in skin thrombotic syndrome associated with antiphospholipid antibodies, that is, microthrombi in dermal vessels without inflammation. In addition to indicating antiphospholipid antibodies in apparently healthy patients, this sign could be a marker of risk for large-vessel thrombosis.