B12 deficiency pernicious anemia symptoms
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Symptoms of Vitamin B12 Deficiency and Pernicious Anemia
Introduction to Pernicious Anemia and Vitamin B12 Deficiency
Pernicious anemia (PA) is a condition resulting from vitamin B12 deficiency, often due to autoimmune destruction of gastric parietal cells or intrinsic factor, which are essential for B12 absorption 45. This deficiency can lead to a range of hematological, neurological, and psychiatric symptoms 34.
Hematological Symptoms
Anemia and Macrocytosis
The most characteristic hematological manifestation of vitamin B12 deficiency is megaloblastic anemia, which presents with high mean corpuscular volume (MCV) and hypersegmented neutrophils . Patients often exhibit symptoms such as fatigue, pallor, tachycardia, and lightheadedness due to anemia . In some cases, neutropenia and thrombocytopenia can occur, mimicking conditions like aplastic anemia or leukemia .
Hemolysis and Pseudothrombotic Microangiopathy
Although rare, hemolysis can occur in PA, presenting as hemolytic anemia, thrombocytopenia, and schistocytosis, which can be mistaken for thrombotic microangiopathy 58. This highlights the importance of distinguishing PA from other hematological disorders for appropriate management.
Neurological Symptoms
Peripheral Neuropathy and Ataxia
Vitamin B12 deficiency can lead to progressive neuro-psychiatric symptoms, including peripheral numbness, paresthesias, weakness, and ataxia . These symptoms are due to impaired myelinogenesis, which affects nerve function .
Cognitive and Psychiatric Manifestations
PA can present with various psychiatric symptoms such as depression, mania, psychosis, and cognitive impairments, including memory and attention problems 110. In some cases, psychiatric symptoms may precede hematological and neurological abnormalities, making early diagnosis challenging 110.
Oral and Gastrointestinal Symptoms
Glossitis and Stomatitis
Oral manifestations of vitamin B12 deficiency include glossitis, stomatitis, and mucosal ulceration, which can occur even in the absence of symptomatic anemia or macrocytosis . These symptoms are often overlooked but can be critical indicators of underlying B12 deficiency.
Gastrointestinal Atrophy
Chronic atrophic gastritis, often associated with Helicobacter pylori infection, is a common finding in patients with PA. This condition leads to reduced gastric acid and intrinsic factor production, further exacerbating B12 deficiency .
Conclusion
Pernicious anemia and vitamin B12 deficiency present with a wide array of symptoms affecting multiple systems. Hematological symptoms like anemia and macrocytosis, neurological issues such as peripheral neuropathy and cognitive impairments, and oral manifestations like glossitis are common. Early recognition and treatment of these symptoms are crucial to prevent irreversible damage and improve patient outcomes.
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