Testing for tuberculosis recommended only for those at risk

Ask Dr. Keith Roach M.D

DEAR DR. ROACH: I am a nursing student in my 30s and originally from the Philippines. As part of my testing, I had a skin test for tuberculosis, which was positive. I had a friend in the hospital recently with tuberculosis. My doctor has recommended that I get treated for latent tuberculosis. What does this mean? — A.C.S. ANSWER: Most people who are exposed to tuberculosis will not develop the disease. Some people will develop “latent” infection. This means there is active tuberculosis bacteria in their body, but their system is keeping it from becoming a full-blown infection. People in this situation are at risk of the latent tuberculosis escaping the immune system and developing into tuberculosis. Treatment of the latent tuberculosis is intended to reduce the risk of this happening. Testing is recommended only for people who are likely to be treated. You have two reasons to be tested: First, as a health care worker — congratulations on becoming a nurse, we need you! — you are at risk of acquiring tuberculosis infection and should be screened. Second, people born in the Philippines are at risk for having acquired tuberculosis, often in childhood. People in their 30s are generally at very low risk of serious side effects from the medications used to treat latent tuberculosis infection. Isoniazid (INH) and rifampin are the medicines commonly used. Since the risk of developing disease later in life is much higher than the risk of a serious side effect, treatment is recommended in your case. *** DEAR DR. ROACH: I’m an 85-year-old woman with no major health problems. I lead an active life and exercise daily. About four years ago, I began being bothered by cold feet at night. At first, I could just wear socks to bed. Now I must put my feet in an electric heated pouch in my bed, which doesn’t stay in place. When I travel, I take the heated insoles skiers use to keep their feet warm. Without some device, I’m kept awake by a feeling of icy soles. I am not diabetic. I’ve described the problem to a neurologist, a rheumatologist and my primary caregiver. No one has explained what causes the icy feet or if there’s any cure. Is there one? — J.S. ANSWER: There are quite a few possible causes for your cold feet, and your doctors need to first identify why they are cold. To do this, they should start by checking the blood flow to the feet. At age 85, the likelihood of blockages to the arteries in your feet are pretty high. A simple test can make the diagnosis. Since blockages in the feet predict blockages in the heart too, it’s important to know. Treatment can improve symptoms as well as reduce risk of a heart attack. Severe anemia and low thyroid levels can cause very cold feet. Nerve damage is common in diabetes and unusual without it, but a neurologist should have found physical findings for neurologic causes. Raynaud’s syndrome, which usually happens in the hands, occasionally affects the feet preferentially to the hands. Medicines, especially beta blockers, can cause cold feet. Sometimes there isn’t a known cause, and physicians are left advising on treatments to relieve symptoms. I wouldn’t give up before a circulation test, however.