Managing Infections and Low White Blood Cell Counts
by Carlton G. Brown, PhD, RN, AOCN
A low white blood cell count is a common side effect of some cancers and cancer treatment. When your white blood cell count is too low, you have a high risk of getting an infection. Infections can be very serious in people with cancer. If you get an infection or if your white blood cell count is very low, your chemotherapy may be delayed, and you may need to be treated in the hospital.
What causes low white blood cell counts and infections in people with cancer?
White blood cells are part of your immune system, your body’s built-in defense against infection. A healthy immune system contains several types of white blood cells. Each cell type plays a slightly different role in protecting you from infection. The most numerous white blood cells are called neutrophils. They are the “first responders” to viruses, bacteria, and other invaders that can cause an infection.
Similar to other white blood cells, neutrophils are made in the bone marrow. Each neutrophil takes 10 to 14 days to become fully mature. It then has a lifespan of hours. So the bone marrow has to keep making new neutrophils to maintain the body’s supply.
Cancer is caused by rapid, out-of-control cell growth. Chemotherapy and radiation work by taking aim at cells that are multiplying rapidly. Unfortunately, they often damage healthy cells as well as cancerous ones.
Neutrophils are always multiplying rapidly because the immune system is always making new ones. But when the immune system is damaged by chemotherapy, it stops making new neutrophils to replace the old ones. When this happens, the body quickly runs low on neutrophils.
So, a “low white blood cell count” usually means a low neutrophil count. A low neutrophil count is also called neutropenia. When you have a low neutrophil count, your immune system can’t do its job of protecting you from infection as well as it normally does. When your immune system is weakened in this way, it is said to be suppressed.
A shortage of white blood cells can be short term (lasting less than 10 days) or long term (lasting more than 10 to 14 days). With many chemotherapy drugs, the number of white blood cells drops to its lowest level between 7 and 10 days after treatment. This point is called the nadir. Your risk of getting an infection is highest when levels of white blood cells are very low.
What are the symptoms of an infection caused by a low white blood cell count?
When your white blood cell count is low, a fever is the most common sign of an infection. A fever means a body temperature higher than 100.4°F (38°C). Contact a member of your healthcare team right away if you are running a fever. Also, talk with a member of your healthcare team about how best and how often to check your temperature. It can be very dangerous to have a fever of 100.4°F (38°C) or higher for a prolonged period of time without seeing a healthcare provider. This elevated temperature could be the result of a serious infection.
- People aged 65 or older
- Women
- People who have other health problems as well as cancer (for example, diabetes; high blood pressure; and heart, kidney, or liver disease)
- People who have trouble eating a healthy diet while being treated for cancer
- People with cancers of the blood (for example, leukemia and lymphoma)
- People receiving their first cycle of chemotherapy
- People receiving high doses of chemotherapy
- People treated with radiation before chemotherapy, or with radiation and chemotherapy at the same time
- People who have developed a low white blood cell count when they had chemotherapy in the past
Other symptoms may also be a signal that you have an infection. Contact a member of your healthcare team right away if you have any of these symptoms:
- chills or sweating
- difficulty breathing
- difficulty passing urine
- diarrhea
- stomach pain
- discomfort in your rectum
- tenderness in your sinuses (the air chambers in the bone behind your cheeks, eyebrows, and jaw)
- redness or swelling at any site where a tube, or catheter, has been placed in your body
How do I know if I have a low white blood cell count?
Blood tests can tell if you have a low white blood cell count. If your white blood cell count is low or you have a fever, your doctor may order other tests to find out if you have an infection and, if so, what type of infection that you have. These other tests may include a chest X-ray, lung function tests, or a computed tomography (CT) scan.
You may not be able to prevent a low white blood cell count, but you can take some simple steps to reduce your risk of getting an infection.
Can I do anything to prevent a low white blood cell count or an infection?
You may not be able to prevent a low white blood cell count, but you can take some simple steps to reduce your risk of getting an infection.
- Wash your hands. Always wash your hands before cooking or eating, and after coughing, sneezing, or using the bathroom. Keeping hands clean is one of the simplest and most effective ways to keep an infection from spreading. Wash hands thoroughly with soap and warm water. If no soap and water is handy, use a water-free sanitizing gel.
- Avoid crowds. Do your shopping and other errands during off hours and not on weekends when grocery stores and other public places are more crowded. It might be important to avoid being around other sick people, especially children.
- Get your flu shot. Get a flu shot every year in the fall or early winter. If you have not had a flu shot within the past year, get one before you start chemotherapy. Some people with cancer should also get a shot that protects against a type of pneumonia. Ask a member of your healthcare team if this shot is right for you.
People who have had a bone marrow or stem cell transplant should avoid all raw food and eat only food that has been well cooked. For other people with low white blood cell counts, however, studies have not shown that food restrictions are helpful for preventing infections.
Can any medications prevent or treat infections caused by a low white blood cell count?
Your doctor may want you to take a drug that speeds up the growth of white blood cells. These drugs are known as colony-stimulating factors. CSFs are lab-made versions of proteins your body makes to help stimulate white blood cell growth. Studies show that you are less likely to get a fever or very low white blood cell counts when you take CSFs during chemotherapy. CSFs are given as shots or injections. You may get the first shot a day or two after you receive chemotherapy, and then every day for the next couple of weeks.
If your white blood cell count is very low or you have an infection or a fever, your doctor may prescribe antibiotics. Be sure to take the antibiotics exactly as your doctor tells you to. Even if your fever goes away, make sure you keep taking the pills for the number of days your doctor says to take them. Some people might be admitted to a hospital for IV antibiotics if their healthcare provider determines that it is important.
Excerpted with permission from A Patient’s Guide to Cancer Symptom Management, by Carlton G. Brown, PhD, RN, AOCN®, copyright © 2011 by the Oncology Nursing Society. All rights reserved.
This article was published in Coping® with Cancer magazine, May/June 2012.
