Hair-on-End Sign in a 9-Year-Old Girl Presenting with Acute Stroke in Sickle Cell Disease

Abstract

Background: The hair-on-end (HOE) sign is a rare finding seen in the diploic space on skull radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) with the appearance of long, thin vertical striations of calcified spicules perpendicular to the bone surface that looks like hair standing on end. It is classically seen in children/adolescents with hemolytic anemias, in particular, thalassemia major and sickle cell disease. Here, we present a 9-year-old Ugandan girl who presented with stroke in whom head CT demonstrated cerebral intraparenchymal hemorrhage and multiple infarcts on the left with HOE sign. Hb electrophoresis confirmed the diagnosis of sickle cell anemia. Case Summary: We present a 9-year-old Ugandan girl who presented with an unexplained stroke that preceded an episode of acute headache, vomiting, followed by focal convulsions and altered consciousness. Clinical findings revealed severe pallor of the conjunctivae and mild scleral icterus. CT demonstrated right cerebral intraparenchymal hemorrhage, multiple high cerebral infarcts on the right and evidence of extra medullary hematopoiesis with a classical HOE sign. Hemoglobin (Hb) electrophoresis confirmed sickle cell disease (SCD). The child was then initiated on hydroxyurea, antibiotics, analgesics and intravenous fluids. She improved and was discharged 16 days later. Follow-up of the child was uneventful. Conclusion: HOE sign is a complication of chronic hemolysis usually seen in patients with thalassemia and sickle cell anemia. It is a rare finding that clinicians should be well conversant with, especially in Africa where sickle cell disease is common.