Comment
More than 50 years after the first case of SS was diagnosed, better laboratory workup is available and more information is known about the pathophysiology. Sneddon syndrome is a rare disorder, affecting only approximately 4 patients per million each year worldwide. Seronegative antiphospholipid antibody syndrome (SNAPS) describes patients with clinical presentations of antiphospholipid syndrome (APS) without detectable serological markers.7 Antiphospholipid-negative SS, which was seen in our patient, would be categorized under SNAPS. A PubMed search of articles indexed for MEDLINE using the terms livedo racemosa, Sneddon syndrome, and SNAPS and splenomegaly revealed there currently are no known cases of SNAPS that have been reported with splenomegaly and lymphadenopathy. Our patient presented with the following clinical features of SS: livedo racemosa, history of miscarriage, psychiatric disturbances, and hypertension. Surprisingly, biopsies from affected skin did not show any fibrin deposition or microthrombi but did reveal perivascular lymphocytic infiltrations. Magnetic resonance imaging did not show any pathological lesions or vascular changes.
Sneddon syndrome and APS share a common pathway to occlusive arteriolopathy for which 4 stages have been described by Zelger et al.5 Stage I involves a nonspecific Langerhans cell infiltrate with polymorphonuclear leukocytes. The tunica media and elastic lamina usually are unaltered at this early stage, while the surrounding connective tissue may appear edematous.5 This early stage of histopathology has not been evaluated in SS patients, primarily because of delay of diagnosis. Late stages III and IV will show fibrin deposition and shrinkage of affected vessels.7
A PubMed search using the terms Sneddon syndrome, lymphadenopathy and livedo racemosa, and Sneddon syndrome and lymphadenopathy revealed that splenomegaly and lymphadenopathy have not been reported in patients with SS. In patients with antiphospholipid-negative SS, one can assume that antibodies to other phospholipids not tested must exist because of striking similarities between APS and antiphospholipid-negative SS.8 Although our patient did not test positive for any of these antibodies, she did present with lymphadenopathy and splenic enlargement, leading us to believe that involvement of the reticuloendothelial system may be a feature of SS that has not been previously reported. Further studies are required to name specific antigens responsible for clinical manifestations in SS.
Currently, no single diagnostic test for SS exists, thus delaying both diagnosis and initiation of treatment. Histopathologic examination may be helpful, but in many cases it is nonspecific, as are serologic markers. Neuroradiological confirmation of involvement usually is the confirmatory feature in many patients with late-stage diagnosis.2 A diagnostic schematic for SS, which was first described by Daoud et al,2 illustrates classification of symptoms and aids in diagnosis. A working diagnosis of idiopathic livedo racemosa is made after ruling out other causes of SS in a patient with nonspecific biopsy findings and negative magnetic resonance imaging results with prodromal symptoms. The prognosis for such patients progressing to full SS is unknown with or without management using anticoagulant therapy.
Conclusion
Early diagnosis of livedo racemosa and SS is essential, as prevention of cerebrovascular accidents, myocardial infarction, and other thromboembolic diseases can be minimized by attacking risk factors such as smoking, taking oral contraceptive pills, becoming pregnant,9 and by initiating either antiplatelet or anticoagulation treatments. These treatments have been shown to delay the development of neurovascular damage and early-onset dementia. We present this case to demonstrate the variability of early-presenting symptoms in idiopathic livedo racemosa. Recognizing some of the early manifestations can lead to early diagnosis and initiation of treatment.