Pernicious Anemia Differential Diagnoses
- Author: Paul Schick, MD; Chief Editor: Emmanuel C Besa, MD more...
Diagnostic Considerations
By definition, pernicious anemia refers specifically to vitamin B-12 deficiency resulting from a lack of production of intrinsic factor (IF) in the stomach. However, vitamin B-12 absorption is a complex process, and other causes of vitamin B-12 deficiency exist. Pernicious anemia must be differentiated from other disorders that interfere with the absorption and metabolism of vitamin B-12 and produce cobalamin deficiency, with the development of a macrocytic anemia and neurologic complications.
Go to Anemia, Iron Deficiency Anemia, and Chronic Anemia for complete information on these topics.
Other conditions to be considered include the following:
- Cestode infection
- Neurologic disorders
- Senility
Differential Diagnoses
- Achlorhydria
- Alcoholic Fatty Liver
- Alcoholic Hepatitis
- Anemia
- Aplastic Anemia
- Bone Marrow Failure
- Celiac Sprue
- Cirrhosis
- Folic Acid Deficiency
- Gastric Cancer
- Gastritis, Atrophic
- Hemolytic Anemia
- Hyperbilirubinemia, Unconjugated
- Hyperthyroidism
- Hypothyroidism
- Immune Thrombocytopenic Purpura
- Iron Deficiency Anemia
- Macrocytosis
- Malabsorption
- Megaloblastic Anemia
- Myeloproliferative Disease
- Neutropenia
- Schizophrenia
- Sprue, Tropical
- Zollinger-Ellison Syndrome
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Elmadfa I, Singer I. Vitamin B-12 and homocysteine status among vegetarians: a global perspective. Am J Clin Nutr. May 2009;89(5):1693S-1698S. [Medline].
Chan JC, Liu HS, Kho BC, Lau TK, Li VL, Chan FH, et al. Longitudinal study of Chinese patients with pernicious anaemia. Postgrad Med J. Dec 2008;84(998):644-50. [Medline].
Andrès E, Vogel T, Federici L, Zimmer J, Ciobanu E, Kaltenbach G. Cobalamin deficiency in elderly patients: a personal view. Curr Gerontol Geriatr Res. 2008;848267. [Medline].
Erkurt MA, Aydogdu I, Dikilitas M, Kuku I, Kaya E, Bayraktar N, et al. Effects of cyanocobalamin on immunity in patients with pernicious anemia. Med Princ Pract. 2008;17(2):131-5. [Medline].
Patient Condition | Methylmalonic Acid | Homocysteine |
Healthy | Normal | Normal |
Vitamin B-12 deficiency | Elevated | Elevated |
Folate deficiency | Normal | Elevated |
Patient Condition | Stage I Water | Stage II Intrinsic Factor | Stage III Antibiotic | Stage IV Pancreatic Extract |
Healthy | Normal | … | … | … |
Pernicious anemia | Low | Normal | … | … |
Bacterial overgrowth | Low | Low | Normal | … |
Pancreatic insufficiency | Low | Low | Low | Normal |
Defect in ileum | Low | Low | Low | Low |