Pernicious Anemia

Pernicious anemia is a type of vitamin B12 deficiency anemia that occurs when the body is unable to absorb vitamin B12 from food. This condition is caused by a lack of intrinsic factor, a protein in the stomach that plays a crucial role in the absorption of vitamin B12.

Causes

Pernicious anemia is often caused by an autoimmune response, where the immune system mistakenly attacks the cells in the stomach that produce intrinsic factor. This can lead to a decrease in the production of intrinsic factor, making it difficult for the body to absorb vitamin B12 from food. Other causes of pernicious anemia include:

• Pernicious anemia can also be caused by surgical removal of part or all of the stomach (gastrectomy)
• Certain medications, such as proton pump inhibitors and H2 blockers, that reduce stomach acid production
• Conditions that affect the small intestine, such as celiac disease, Crohn's disease, and bacterial overgrowth

Symptoms

The symptoms of pernicious anemia can develop slowly over time and may include:

• Fatigue and weakness
• Shortness of breath
• Dizziness or lightheadedness
• Pale skin
• Headaches
• Loss of appetite
• Numbness or tingling in the hands and feet
• Difficulty walking
• Diarrhea or constipation

Diagnosis

Pernicious anemia is typically diagnosed through a combination of physical examination, medical history, and laboratory tests. These tests may include:

• Complete blood count (CBC) to check for anemia
• Vitamin B12 level test to check for deficiency
• Intrinsic factor antibody test to check for autoimmune response
• Gastrointestinal endoscopy or upper GI series to rule out other conditions

Treatment

Treatment for pernicious anemia typically involves vitamin B12 supplements, which can be given orally or through injections. The goal of treatment is to restore normal levels of vitamin B12 in the body and prevent further complications.

• Vitamin B12 injections are usually given monthly
• Oral vitamin B12 supplements may be prescribed for people with mild deficiency
• Dietary changes, such as increasing intake of vitamin B12-rich foods (e.g., meat, fish, poultry, eggs, and dairy products)

Complications

If left untreated, pernicious anemia can lead to serious complications, including:

• Nerve damage (neuropathy)
• Increased risk of infections
• Increased risk of heart problems
• Cognitive impairment and dementia

Prognosis

With proper treatment, most people with pernicious anemia can recover fully and lead normal lives. However, it is essential to continue taking vitamin B12 supplements for the rest of their lives to prevent relapse.