Doc: Reader’s blood-loss-induced anemia cause elusive

Dear Dr. Roach: My mother, who is now 81, has very low iron. She has to have iron infusions. The infusions last from six to eight weeks. Afterward, the iron level is fine for a little while, and then she has to go back again. They have done several tests, including a colonoscopy and a bone marrow biopsy, but they don’t know why she is losing blood or where it is going. This has been going on for way too long. She also has said that her siblings have to take iron supplements, but she is the only one losing blood and having transfusions.

V.C.D.

Dear V.C.D.: I have seen people hospitalized with this condition because the blood loss is so much of a problem. It sounds like your mother’s blood loss isn’t quite that rapid, but here are some lessons I’ve learned from taking care of many people like your mother.

By far the most common place to lose blood is in the GI tract, but it can happen anywhere from the mouth to the anus. The colon is the first place to look, and sometimes the source of blood loss can be missed on the first colonoscopy, especially if the preparation wasn’t perfect. I don’t think they would have missed a cancer or a large polyp, but small abnormal connections between arteries and veins, called AV malformations, can bleed. They might be a source of blood loss. Because the blood contains iron, the blood has to leave the body in order for iron levels to go down. A second colonoscopy may be necessary.

However, other parts of the GI tract can be affected, especially the stomach, the small bowel and the liver and biliary tract. A bleeding scan, done with radioactively tagged red blood cells, can find small amounts of bleeding, but the bleeding has to be active at the time of the scan. I’ve seen a few cases of nosebleeds causing this problem, when the blood went backward, down the esophagus, rather than out the nostrils. Blood loss from the bladder is a rare cause.

Sometimes the problem is absorption. Several conditions can keep the body from absorbing iron, the most common of which is celiac disease. Given the family history, that might be worth testing for.

Dear Dr. Roach: My daughter was diagnosed with an external ear infection. Can you tell MRSA from a regular infection just by looking at it?

J.M.B.

Dear J.M.B.: No, there is no reliable way of telling MRSA (methicillin-resistant Staphylococcus aureus) from the regular methicillin-sensitive Staphylococcus aureus just by visual inspection. A laboratory test is required; however, there are new methods that can do so very quickly.

Many areas have such high rates of MRSA that it’s wise to choose treatment that is effective against MRSA even before testing. In the case of an external ear infection, which is treated with antibiotic drops, not oral antibiotics (except in very deep infections or in people with immune system disease), there are several options that are effective against MRSA and MSSA, including ciprofloxacin and the combination of neomycin and polymyxin B.

Email questions to ToYourGoodHealth@med.cornell.edu.