Clinical Images: Vasculitic rash as a presenting symptom of heparin‐induced thrombocytopenia in a woman with primary antiphospholipid syndrome

The patient, a 32-year-old G3P0121 (three pregnancies, zero term infants, one preterm infant, two abortions, one living child) woman with a four-year history of primary antiphospholipid syndrome (APLS), presented with five days of joint pain and one day of rash. Her past APLS manifestations included the following: deep vein thrombosis (DVT), two spontaneous abortions at <10 weeks’ gestation, and pre-eclampsia and hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome requiring preterm emergent cesarean section in her most recent pregnancy despite consistent receipt of therapeutic-dose enoxaparin and low-dose aspirin. On physical examination, she had several erythematous papules on her (A) right earlobe and (B) anterior neck and tenderness of multiple small hand joints and lumbar paraspinal muscles without synovitis or joint effusions. Current anticoagulation was enoxaparin 1 mg/kg twice a day, changed from warfarin two weeks prior in preparation for another pregnancy. Laboratory testing showed elevated anti-phospholipid antibodies: 79.8 U/mL β-2-glycoprotein-1 IgG, >150 U/mL β-2-glycoprotein-1 IgM, 93.1 U/mL cardiolipin IgG, and >150 U/mL cardiolipin IgM (normal <15.0 U/mL for all) and >150 U phosphatidylserine/prothrombin IgG (normal <30.0 U). Patient had normal platelets and negative antinuclear antibody, extractable nuclear antigens, anti-neutrophil cytoplasmic antibodies, rheumatoid factor, anti-cyclic citrullinated peptide antibodies, cryoglobulins, and urine drug screen. (C) Skin biopsy, hematoxylin and eosin staining at 100× magnification, showed dilated superficial vessels with extensive thrombosis and fibrinoid necrosis of vessel walls (black arrow) with perivascular neutrophils, karyorrhexis, and erythrocyte extravasation (white arrow) consistent with leukocytoclastic vasculitis with vasculopathy. Corticosteroids, low-dose aspirin, and hydroxychloroquine were started for presumptive thrombotic complications of APLS. Over three days, platelet count fell 30% to 50% with nadir of 121,000/mm3. Right brachial vein DVT developed. Her 4Ts score was 6, indicating high pretest probability of heparin-induced thrombocytopenia (HIT), and detection of heparin/platelet factor 4 antibodies confirmed HIT diagnosis.1 Enoxaparin was changed to fondaparinux and prednisone tapered. Two months later, the patient conceived. With maintaining therapeutic fondaparinux plasma concentrations, the pregnancy was uncomplicated, and she delivered a healthy baby at term. Guidance for managing comorbid APLS and HIT during pregnancy is limited.2, 3 Diagnostic overlap and management complexities underscore the need for tailored anticoagulation strategies in patients with APLS and HIT, particularly during pregnancy. Augusta University does not require institutional review board approval for the publication of case studies involving five or fewer patients, as in this report. A written informed consent to publish this paper has been obtained from the patient and is available on request. Disclosure Form: Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.