White blood cells are produced by your bone marrow to help your body fight infection. If you have fewer than normal white blood cells, you have a higher risk of getting an infection. When you have a low white blood cell count, your immune system isn't working as well as it should. Doctors call this "immunocompromised." If you're immunocompromised, you have a higher risk of getting sick from a bacterium or virus that doesn't affect people with a healthy immune system.
Breast cancer treatments that can lower your white blood cell count:
- Abraxane (chemical name: albumin-bound or nab-paclitaxel)
- Adriamycin (chemical name: doxorubicin)
- carboplatin (brand name: Paraplatin)
- Cytoxan (chemical name: cyclophosphamide)
- Doxil (chemical name: doxorubicin)
- Ellence (chemical name: epirubicin)
- fluorouracil (also called 5-fluorouracil or 5-FU; brand name: Adrucil)
- Gemzar (chemical name: gemcitabine)
- Halaven (chemical name: eribulin)
- Mitomycin (chemical name: mutamycin)
- mitoxantrone (brand name: Novantrone)
- Navelbine (chemical name: vinorelbine)
- Taxol (chemical name: paclitaxel)
- Taxotere (chemical name: docetaxel)
- thiotepa (brand name: Thioplex)
- radiation therapy
- some targeted therapies:
- Avastin (chemical name: bevacizumab)
- Enhertu (chemical name: fam-trastuzumab-deruxtecan-nxki)
- Herceptin (chemical name: trastuzumab)
- Herzuma (chemical name: trastuzumab-pkrb)
- Ibrance (chemical name: palbociclib)
- Kisqali (chemical name: ribociclib, formerly called LEE011)
- Lynparza (chemical name: olaparib)
- Ogivri (chemical name: trastuzumab-dkst)
- Perjeta (chemical name: pertuzumab)
- Piqray (chemical name: alpelisib)
- Talzenna (chemical name: talazoparib)
- Tykerb (chemical name: lapatanib)
- Verzenio (chemical name: abemaciclib)
- Tecentriq (chemical name: atezolizumab), an immunotherapy
If you get an infection because you have a low white blood cell count, your symptoms may include:
- fever (call your doctor immediately if your fever is higher than 101.5 degrees F)
- sore throat or cough
- shortness of breath
- nasal congestion
- vaginal discharge, itching, or burning during urination
- an injury site becomes red, swollen, or warm
Boosting your white blood cell count
If you have a low white blood cell count, your doctor can prescribe medicines to help stimulate your immune system after each round of chemotherapy. Your doctor also may decide to stop your chemotherapy treatment for a little while so your body can recover and make more white blood cells.
Things to consider if you have a low white blood cell count
If you have a low white blood cell count, consider taking the following steps to avoid infection:
- Avoid large crowds of people during the cold and flu season. Germs can spread easily through coughing and sneezing.
- Pay attention to notices about food-borne illness outbreaks. If you have a weakened immune system, you have a higher risk of becoming dangerously ill from Listeria, E. coli, and Salmonella bacteria, as well as Shiga toxin. All these bacteria have caused food recalls in the last several years. Avoid any foods that have been recalled. Follow the U.S. Department of Health and Human Services “Clean, Separate, Cook, and Chill” steps when preparing and storing food. Eating a healthy diet can help you get the nutrients you need to fight infection.
- Avoid swimming or wading in lakes, streams, and ponds. Cryptosporidium is a microscopic parasite that is one of the most common causes of water-borne disease in the United States. It gets into water through the feces of infected animals, such as raccoons, squirrels, and deer. If you’re immunocompromised, you have a higher risk of becoming dangerously ill from Cryptosporidium.
- Prevent mosquito bites. Mosquitoes can carry West Nile virus, an illness that can be very serious for immunocompromised people. When you go outside, use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535, ingredients that are recommended by the U.S. Centers for Disease Control. Avoid going outside at dawn and dusk and wear long sleeves and long pants when you do go out. Also, make sure your window and door screens don’t have any holes in them.
- Wash your hands frequently and have the people you spend time with do the same.
- Prevent cuts and scrapes. Wear gloves when gardening, take care when clipping finger/toe nails, and use caution when handling knives and scissors.
- Don’t pick at scabs or pimples -- they can become infected if the wound is opened.
- Don't have dental work while your white blood cell count is low; cuts in your mouth might lead to infection.
Learn more on our Eating When You Have a Weakened Immune System page.
Low White Blood Cell Counts and Infection Risk
Brian Wojciechowski, M.D. explains different types of white blood cells, how breast cancer treatment lowers their levels, and what low white blood cell levels mean for your risk of infection.