Symptoms of Pernicious Anemia
Pernicious anemia presents with a combination of hematological, gastrointestinal, and neurological symptoms due to vitamin B12 deficiency caused by intrinsic factor deficiency.
Common Clinical Manifestations
Hematological Symptoms
- Fatigue and weakness due to reduced oxygen-carrying capacity 1, 2
- Pallor (pale appearance) of skin and mucous membranes 1, 3
- Shortness of breath and exercise dyspnea, particularly with exertion 1, 3
- Tachycardia and systolic flow murmurs as compensatory mechanisms 1, 4
Gastrointestinal Symptoms
- Glossitis (smooth, red, and sometimes painful tongue) 1, 5
- Angular stomatitis (cracking or inflammation at the corners of the mouth) 1, 2
- Anorexia and weight loss 4, 5
- Diarrhea in some cases 3, 5
Neurological Symptoms
- Paresthesias (tingling and numbness), particularly in extremities 2, 6
- Ataxia (loss of coordination) and gait disturbances 3, 6
- Decreased position and vibration sense 6
- Muscle weakness, particularly in lower extremities 3, 6
- Hyperreflexia 6
- In severe cases, subacute combined degeneration of the spinal cord 7, 6
Neuropsychiatric Symptoms
- Depression and mood changes 3, 6
- Memory impairment and cognitive dysfunction 4, 6
- Psychotic episodes in some cases 3, 6
- Alterations to vision and smell 6
Other Clinical Findings
- Koilonychia (spoon-shaped nails) 1
- Blue sclerae (bluish discoloration of the whites of the eyes) 1
- Pagophagia (craving for ice) 1
- Restless legs syndrome 1
- Urinary incontinence in advanced cases 6
Laboratory Findings
- Macrocytic anemia with elevated mean corpuscular volume (MCV) >100 fL 3, 6
- Hypersegmented neutrophils on peripheral blood smear 3
- Low vitamin B12 (cobalamin) levels 4, 3
- Elevated methylmalonic acid (MMA) and homocysteine levels 7, 3
- Positive intrinsic factor antibodies and/or parietal cell antibodies 4, 5
Important Considerations
- Neurological symptoms may occur without significant anemia in approximately one-third of cases 7, 6
- Early diagnosis is crucial as some neurological complications may become irreversible despite treatment 2, 6
- Pernicious anemia is frequently associated with other autoimmune disorders, particularly autoimmune thyroid disease (40%) and diabetes mellitus (10%) 5
- The disease is often insidious in onset and progression, with patients becoming acclimatized to symptoms 2
- Pernicious anemia represents 20%-50% of vitamin B12 deficiency causes in adults 4
Warning Signs Requiring Urgent Attention
- Severe neurological deficits suggesting subacute combined degeneration of the spinal cord 7, 6
- Profound anemia with hemoglobin levels <7 g/dL 3
- Signs of heart failure due to severe anemia 1
- Psychotic symptoms or significant cognitive impairment 3, 6
Early recognition and treatment with vitamin B12 replacement can prevent irreversible neurological damage and effectively manage hematological abnormalities 7, 6.