Pernicious anemia is an autoimmune disease, a form of megaloblastic anemia. Humans do not produce vitamin B12, it must be obtained through their diet, they need this very important vitamin to make red blood cells. For B12 to be able to be absorbed properly, it must first be bound by intrinsic factor which is found in the small bowel. When someone has pernicious anemia, it is thought that their body mistakenly attacks the intrinsic factor and/or the B12, without the intrinsic factor bound B12 their bodies can not make new blood cells and as each day old blood cells die, eventually the person suffering from this disease will start to become weak, and in times past die, from lack of blood. Humans get B12 through meat and dairy products. Those who don’t eat meat nor dairy products can suffer from B12 deficiency which is just like suffering from pernicious anemia other than it is curable simply by adjusting their diet to include all the important food groups or by taking B12 vitamins. People of European heritage are most prone to pernicious anemia and it is a disease that is most often seem in individuals over 60 years old. In North America about 15 people out of 100,000 are diagnosed with it each year. Someone who is diagnosed with pernicious anemia will have it for life, there is no cure for the disease, but is easily controlled.
The human body stores B12 in the liver for 3-5 years, so it takes a few years before symptoms begin to appear. Sadly damage to the nervous system can be done before the disease is discovered. Many of the symptoms are related to the lack of oxygen carrying blood in ones body, such as a lack of energy, tiredness and shortness of breath. Other symptoms include a sore swollen tongue, weight loss, clumsiness, low blood pressure, rapid heart beat, diarrhea, memory loss and confusion, numbness and eventually loss of felling in toes and fingers and jaundice. Those who suffer from pernicious anemia are more susceptible to gastric cancer.
Diagnosis can be difficult as there is no exact tests for it. Doctors will start with full blood work, often followed by a Schilling test and possibly a couple other tests. Once pernicious anemia has be confirmed the patient will be put on a monthly regime of either B12 shots or daily pills. If the pernicious anemia is well advanced before it is detected, it may be necessary to have a blood transfusion and daily B12 shots will be administered for several days, so the lost blood and B12 can be replenished. The normal person needs 2.4 micrograms of B12 a day, someone with pernicious anemia will have to take about 40-500 times that in a month to be able to absorb the needed amount. Some are lucky enough to take a daily vitamin, normally 1000- 2000 micrograms, others will have to take a monthly shot of around 2000 micrograms. Injections are absorbed far better than oral pills. Many who have to take the shot complain that they often feel tired by the end of the month and that the shot as it is injected into a muscle will often cause a fair amount of pain. Usually the shot is done in the arm. Nasal sprays and behind the ear patches are both being tested as ways to administer the B12.
Pernicious anemia is also called Biermer's or Addison's anemia. The word “pernicious” means deadly and at one time this disease was fatal. The disease was first identified in 1849 by Dr. Addison, but until 1920 all who developed it died from it. In 1920 George Whipple made the discovery that large amounts of liver helped anemia caused by bleeding and from there him and two others, George Minot and William Murphy proceeded to discover a cure. In 1934 the three men shared the Nobel prize in medicine for their work on this once very deadly disease. In 1948 two individual chemist, one from the States and one from England discovered and named the vitamin B12 and thanks to them pernicious anemia is now treatable through injection or large oral dose.