Pernicious Anemia with Neuropsychiatric Dysfunction in a Patient with Sickle Cell Anemia Treated with Folate Supplementation

he administration of folic acid can mask the megaloblastic anemia caused by cobalamin deficiency. [1] 2][3][4][5] More critically, this masking, although neither complete nor permanent, 2-4 can permit neurologic dysfunction to develop and sometimes become irreversible. [1][2 [3][4]6 A few authors have proposed that folate may actually worsen the neurologic dysfunction. 3,7 Patients with sickle cell disease are often routinely given folate supplementation. The rationale is to prevent the deficiency caused by the increased folate turnover in chronic hemolytic anemia. 8 However, clinical folate deficiency rarely occurs in patients with sickle cell disease, and objective evidence of a benefit from such supplementation is sparse. 9 The use of folate supplementation is also based on the assumption that cobalamin deficiency almost never affects patients with sickle cell disease, therefore making folate treatment virtually risk-free. We describe a patient with sickle cell disease in whom neurologic deterioration due to untreated cobalamin deficiency developed during treatment with folate. Her case suggests that routine folate supplementation in patients with sickle cell disease should be approached with caution.