Pernicious anemia
Alerts and Notices
Synopsis
Typical symptoms include malaise, pallor, and dyspnea attributable to anemia. Vitamin B12 deficiency can result in both central and peripheral nervous system manifestations (eg, paresthesias, loss of proprioception, poor concentration, and depression) as well as anosmia and atrophic glossitis. Gastrointestinal symptoms (eg, abdominal pain, diarrhea, and constipation) may be present.
If treated, many of these manifestations are reversible. However, if undiagnosed and untreated, some neurologic manifestations can be permanent. The hallmarks of therapy include vitamin B12 repletion. However, this does not reverse the underlying autoimmune gastritis. If gastrointestinal symptoms develop, patients should be evaluated for gastric cancers given their increased risk.
Codes
ICD10CM:D51.0 – Vitamin B12 deficiency anemia due to intrinsic factor deficiency
SNOMEDCT:
84027009 – Pernicious anemia
Look For
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Malnutrition / eating disorder (anorexia, bulimia) with nutritional vitamin B12 deficiency
- Vegan or vegetarian diet with nutritional vitamin B12 deficiency (dairy and meat are primary sources)
- Imerslund-Grasbeck disease
- Gastric cancer
- Celiac disease
- Tropical sprue
- Inflammatory bowel disease (eg, Crohn disease, ulcerative colitis)
- Bariatric surgery
- Postgastrectomy
- Iatrogenic: medications that block gastric acid
- Nitrous oxide abuse
- Myelodysplastic syndrome
- Hypothyroidism
- Folic acid deficiency
- Small intestinal bacterial overgrowth
- Zollinger-Ellison syndrome
- Gastric outlet obstruction
- Delayed gastric emptying
Best Tests
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Management Pearls
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Therapy
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References
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Last Reviewed:03/15/2018
Last Updated:01/17/2022
Last Updated:01/17/2022
Pernicious anemia