Children's Health and Wellness

Megaloblastic (Pernicious) Anemia in Children

What is megaloblastic anemia?

Megaloblastic anemia is a type of anemia characterized by very large red blood cells. In addition to the cells being large, the inner contents of each cell are not completely developed. This malformation causes the bone marrow to produce fewer cells, and sometimes the cells die earlier than the 120-day life expectancy. Instead of being round or disk-shaped, the red blood cells can be oval.

What causes megaloblastic anemia?

There are many causes of megaloblastic anemia, but the most common source in children occurs from a vitamin deficiency of folic acid or vitamin B12. Other sources of megaloblastic anemia include the following:

  • Digestive diseases. Certain diseases of the lower digestive tract can lead to megaloblastic anemia. These include celiac disease, chronic infectious enteritis, and enteroenteric fistulas. Pernicious anemia is a type of megaloblastic anemia caused by an inability to absorb vitamin B12 due to a lack of intrinsic factor in gastric (stomach) secretions. Intrinsic factor enables the absorption of vitamin B12.

  • Malabsorption. Inherited congenital folate malabsorption, a genetic problem in which infants can't absorb folic acid in their intestines, can lead to megaloblastic anemia. This requires early intensive treatment to prevent long-term problems, such as intellectual disability.

  • Medication-induced folic acid deficiency. Certain medications, specifically ones that prevent seizures, such as phenytoin, primidone, and phenobarbital, can impair the absorption of folic acid. The deficiency can usually be treated with a dietary supplement.

  • Folic acid deficiency. Folic acid is a B vitamin required for the production of normal red blood cells. Folate, the naturally occurring form, is present in foods, such as green vegetables, liver, and yeast. Folic acid is produced synthetically and added to many food items, including breads and cereals.

What are the symptoms of megaloblastic anemia?

The following are the most common symptoms of megaloblastic anemia:

  • Abnormal paleness or lack of color of the skin

  • Decreased appetite

  • Irritability

  • Lack of energy or tiring easily (fatigue)

  • Diarrhea

  • Difficulty walking

  • Numbness or tingling in hands and feet

  • Smooth and tender tongue

  • Weak muscles

The symptoms of megaloblastic anemia may look like other blood conditions or medical problems. Always consult your child's doctor for a diagnosis.

How is megaloblastic anemia diagnosed?

Megaloblastic anemia may be suspected from general findings from a complete medical history and physical exam of your child. In addition, several blood tests can be done to confirm the diagnosis. If the megaloblastic anemia is thought to be caused by a problem in the digestive tract, a barium study of the digestive system may be done, and occasionally an endoscopy may need to be done.

Treatment for megaloblastic anemia

Your baby’s health care provider will figure out the best treatment based on:

  • How old your baby is

  • His or her overall health and medical history

  • How sick he or she is

  • How well your baby can handle specific medications, procedures, or therapies

  • How long the condition is expected to last

  • Your opinion or preference

Treatment for megaloblastic anemia due to a folic acid deficiency usually involves your child taking an oral dietary folic acid supplement for at least 2 to 3 months. If the disorder is caused by an absorption problem in the digestive tract, this may need to be treated first. Vitamin B12 supplements are best absorbed when given by injection. Animal proteins are the only food sources of vitamin B12.

Foods that are naturally rich in folate include the following:

  • Orange juice

  • Oranges

  • Romaine lettuce

  • Spinach

  • Liver

  • Rice

  • Barley

  • Sprouts

  • Wheat germ

  • Soy beans

  • Green, leafy vegetables

  • Beans

  • Peanuts

  • Broccoli

  • Asparagus

  • Peas

  • Lentils

  • Chick peas (garbanzo beans)

Foods that are fortified with folic acid include the following:

  • Breakfast cereals

  • Breads

  • Enriched pasta

  • Enriched rice

Foods that are rich in vitamin B12 include the following:

  • Meat

  • Poultry

  • Milk

  • Shellfish and some fish

  • Eggs

  • Cheese

Online Source: Folate, National Institutes of Health
Online Source: Vitamin B12, National Institutes of Health
Online Source: What is Pernicious Anemia? National Heart Lung And Blood Institute
Online Source: Etiology and clinical manifestations of vitamin B12 and folic acid deficiency, Up to Date
Online Editor: Metzger, Geri K.
Online Medical Reviewer: Foster, Sarah, RN, MPH
Online Medical Reviewer: MMI board-certified, academically affiliated clinician
Date Last Reviewed: 1/7/2015
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