Is Thrombocytopenia Progressing? Immune Thrombocytopenic Purpura as Warning Sign for Significant Blood Disease

Abstract

A previously healthy 6-year-old girl presented to an outside emergency department (ED) with a 1-day history of petechial rash on the wrist and progressively involved both her lower extremities. Parents reported an episode of bleeding gums earlier in the day that resolved prior to arrival. She had an uncomplicated ear infection 1 month before, which was treated with 1 week of amoxicillin. History was negative for recent trauma, nose bleeds, bone or joint pain, itching, sore throat, difficulty breathing, nausea, vomiting, diarrhea, or sick contacts. Past medical history was unremarkable, with no serious illnesses or hospitalizations. Family history was noncontributory with no history of blood dyscrasias. On examination, she was alert, cooperative, and well-appearing. Her vital signs were as follows: temperature 99.5°F, pulse 118 beats/min, respiratory rate 22 breaths/min, blood pressure 109/58 mm Hg, and SpO 2 99% on room air. Skin examination revealed scattered petechiae on her trunk and extremities, with a linear petechial pattern consistent with a recent tourniquet placement for a blood draw. Purpura were present on her lower extremities. Examination of the mouth revealed clotted blood along the gum lines. The nasal mucosa was moist with no evidence of bleeding. The remainder of the examination was unremarkable. Laboratory results showed hemoglobin (Hb) 11.7 g/dL (normal = 11.5-14.3 g/dL), red blood cell (RBC) count 4.1/mm (normal = 4.1-5.2/mm), and white blood cell (WBC) count 4200 cells/mm (normal = 3800-10 400 cells/mm). Absolute neutrophil count (ANC) was 1100 cells/mm (normal = 1500-6500 cells/mm), platelet count was 12 000 cells/mm (normal = 187 000-400 000 cells/mm), and mean platelet volume (MPV) was 7.2 fL (normal = 9.4-12.3 fL). There was no evidence of renal insufficiency to suggest HUS (hemolytic uremic syndrome), and no anemia, schistocytes, or neurological symptoms suggestive of TTP (thrombotic thrombocytopenic purpura). The outside ED made a presumptive diagnosis of acute immune thrombocytopenic purpura (ITP) and administered intravenous immunoglobulin (IVIg) (1 g/kg) for moderately severe bleeding. She thereafter became febrile, nauseous, and developed a headache. Her laboratory results and condition were slow to improve with IVIg, with a drop in Hb to 10.1 g/dL, WBC count to 3000 cells/mm, with an ANC of 1000 cells/mm, and a platelet count of 8000 cells/mm. Five days following presentation, she was referred to the pediatric hematology/oncology department. Her physical examination was significant only for bruising and petechiae, but her Hb was now 9.9 g/dL, WBC count 2500 cells/mm, ANC 200 cells/mm, platelet count 3000 cells/mm, and MPV 7.4 fL. Her blood smear showed normocytic, normochromic RBCs without any blasts or immature cells, while platelets were decreased in number and size. Other laboratory results revealed a reticulocyte count of 0.3% (normal = 0.5% to 1.0%) with normal liver and renal functions, and a normal immunoglobulin profile. She was given another dose of IVIg and underwent a bone marrow aspiration (BMA) and biopsy. It showed no abnormal hematopoietic populations but did reveal <10% cellularity (normal = 60% to 80% in a child) with approximately 77% mature lymphocytes. The results were consistent with aplastic anemia. An extensive viral and molecular workup was inconclusive for any potential etiology for the aplasia. She had a persistent fever with pancytopenia and needed multiple transfusions of both packed RBCs (pRBCs) and apheresis platelets. Piperacillin-tazobactam was used to treat her neutropenic fever. 897363 CPJXXX10.1177/0009922819897363Clinical PediatricsVanderVeen et al research-article2019