Megaloblastic Anemia Presenting as Pyrexia of Unknown Origin

Abstract

Background: An uncommon cause of pyrexia is Vitamin B12 deficiency. Megaloblastic anemia is common in India, but its presentation as pyrexia of unknown origin data is insufficient. We did a prospective study on pyrexia of unknown origin where megaloblastic anemia was the cause. Materials and methods: A study of 74 cases with megaloblastic anemia in adults above 18 years of age during 2 years (January 2019 to December 2020) was conducted at tertiary care hospital. Results: There were 74 patients presenting with PUO and pancytopenia and was diagnosed to have megaloblastic anemia secondary to vitamin B12 and folate deficiency based on peripheral smear. Fever and easy fatigability were the main presenting symptoms. 15 patients had fever of 102 F and fever of more than 2 months. The pyrexia subsided following the vitamin B12 supplementation. Other causes of PUO infective, inflammatory/autoimmune, endocrine causes of pyrexia were excluded by appropriate investigations. Conclusion: Patients presenting with PUO and pancytopenia should be carefully evaluated for simple vitamin B12 deficiency in order to prevent unnecessary use of antibiotics. Megaloblastic anemia due to vitamin B12 deficiency is a reversible cause of pyrexia that should be considered in any patient who presents with pyrexia of unknown origin.