Megalablastic anemia

Overview

Our bodies need vitamin B12 from the food we eat in order to produce sufficient quantities of red blood cells to carry oxygen throughout the body. Sometimes, however, the body loses its ability to absorb this essential vitamin. When this occurs, the assembly line of red blood cell production starts to slow down and we develop pernicious anemia. It can strike just about anyone, but the risk is higher for people of northern European or African descent. It is more common in older adults, occurring in approximately 1% of Canadians who are 60 years of age or above. It is rare in children.

At one time, doctors didn't know a lack of vitamin B12 was the culprit. There were no treatments available and the condition was often fatal, thus the condition's name. Pernicious means "a tendency to cause injury or death".

Today, this ailment is well understood and, once it is diagnosed, it is easy to treat with vitamin B12 pills or injections. These supplements often have to be taken for the rest of one's life.

Symptoms

Symptoms of pernicious anemia usually develop slowly over time. One almost sure sign is a red tongue with a smooth surface. This along with unusual fatigue and weakness are among the most common symptoms. Other signs may include:

  • pale or yellowish skin
  • low-grade fever
  • dizziness when standing up

Infants with pernicious anemia may move in unusual ways and experience delayed development.

If untreated, a person with pernicious anemia may develop some serious complications involving the heart, nerves, brain and digestive tract. Some of the complications are due to the anemia while others are the effect of the vitamin B12 deficiency. Symptoms differ according to the part of the body that's involved:

Heart

  • shortness of breath
  • chest pain
  • heart murmurs
  • rapid heart rate,
  • possible heart failure

Nerves and Brain

  • tingling or numbness in the hands and feet
  • difficulty walking
  • unsteady movements
  • loss of balance
  • sensory changes (vision, taste, smell)
  • loss of memory
  • confusion
  • depression
  • psychosis

Digestive Tract

  • bright red, smooth tongue
  • mouth sores
  • bleeding gums
  • enlarged liver
  • nausea
  • vomiting
  • gas
  • heartburn
  • constipation or diarrhea
  • loss of appetite
  • weight loss

Causes

Now that you know a lack of vitamin B12 is responsible for pernicious anemia - the question is why? Why does the body stop producing sufficient quantities of this essential vitamin? Well, here's what is going on. Certain cells in the lining of the stomach produce something called ·intrinsic factor', a substance which helps the body absorb vitamin B12 in the small intestine. But sometimes, the body's immune system attacks and destroys these cells by mistake. As a result, the lining of the stomach shrinks, the cells are no longer produced and ·intrinsic factor' dries up. Over time, vitamin B12 deficiency develops. This in turn causes pernicious anemia.

Less common causes of pernicious anemia include a diet that is low in vitamin B12, intestinal problems, and certain medications. In some cases pernicious anemia is a direct result of surgery to remove all or part of the stomach. There is also a rare inherited disorder in which children are born without the ability to produce ·intrinsic factor'.

As with many other medical conditions, certain people are at a higher risk for pernicious anemia. These include those with:

  • a family history of pernicious anemia
  • a disorder such as diabetes or a thyroid problem
  • an intestinal disorder that prevents the body from efficiently absorbing vitamin B12

If you are a vegetarian you are also at a higher risk as are alcoholics and the elderly.

Treatment

Treating pernicious anemia is a simple matter of having vitamin B12 injections or taking pills. Pills are taken daily. If you are getting injections, you'll likely be given half a dozen or so in the first few weeks to replenish your liver's store of B12. After that you'll be on a maintenance schedule with regular injections for the rest of your life.