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Fever and neutropenia


What is a fever?

In a child older than 3 months, a fever is:

  • An oral (by mouth) temperature of 100.9 degrees F (38.3 degrees C) or higher;
  • An oral temperature of 100.4 degrees F (38.0 degrees C) or higher that persists for one hour;
  • An under the arm (axillary) temperature of 99.9 degrees F (37.7 degrees C); or
  • An under the arm temperature of 99.4 degrees F (37.4 degrees C) or higher that persists for one hour.

In a child younger than 3 months, a fever is an under-the-arm temperature of 99.4 degrees F (37.4 degrees C) or higher.

To learn the best ways to take a temperature, see “Do You Know… How to Take a Temperature.”

Why is neutropenia?

Neutrophils (NOO truh filz), one type of white blood cell, are counted as part of the Complete Blood Count (CBC). When checking a patient’s neutrophil count, the medical team relies on a count called the Absolute Neutrophil Count (ANC). The ANC gives an estimate of the body’s ability to fight infection, especially bacterial infections. To learn how the staff finds your child’s neutrophil count, see “Do You Know…Calculating the ANC.”

Neutropenia (NOO truh PEE nee uh) is when a person has an abnormally low neutrophil count. It is a common side effect of cancer treatment. Chemotherapy (cancer fighting drugs) usually affects the neutrophil count 7 to 14 days after a dose is received. The length of time it takes your child’s blood counts to drop depends on the dose and type of drug used.

When the ANC is below 500/mm3, the risk of infection is high. During these times, it is important to keep your child away from crowds, especially groups of children. To learn more ways to prevent infection, read “Do You Know… How to Prevent Infection.” In some cases the care team may decide that your child should wear a face mask (particulate mask) to lower the risk of infection. For guidelines on using a face mask, see “Do You Know… How to Use a Particulate Mask.”

When should I check my child's temperature?

You do not have to check your child’s temperature many times throughout the day. If your child is hot to the touch, appears ill, is having chills, or has red cheeks (flushed), he might have a fever. This would be a good time to check your child’s temperature. To learn more about when to check your child’s temperature, see “Do You Know… Signs of an Infection.”

What do I do if my child has a fever?

If you are in Memphis, call your primary clinic Monday through Friday 7:30 a.m.–5 p.m.

After hours or on the weekend, call the main St. Jude number at 901-595-3300 and ask to speak to the doctor on call. You should tell your primary clinic or the doctor on call as soon as you are aware that your child has a fever.

If you are home and not close to Memphis, please call your child’s local doctor or go to the emergency room at your local hospital. Be sure to tell them that your child is a St. Jude patient. They also need to know if your child has a central line and if your child has been receiving chemo or other drugs that suppress the immune system. If you go to a doctor or hospital at home, please call your child’s primary St. Jude clinic during business hours to give them an update on your child’s condition as soon as you can. If you are outside of the Memphis area, dial toll-free 1-886-2STJUDE (1-866-278-5833).

Do not give your child any fever reducing medicines unless your child’s care team has told you to do so.

What to expect when you arrive at St. Jude?

If your child has a fever or other signs of an infection and you come to St. Jude, please register your child right away and get an armband. Then, go directly to your child’s primary clinic (or the Medicine Room if after hours or on the weekend).

The staff will take blood samples including a CBC and blood cultures to check your child’s blood counts and to check for a possible infection source. Your child will probably receive IV fluids and antibiotics.

If your child is neutropenic (ANC less than 500/mm3), the staff will likely admit him to the inpatient unit for observation and antibiotics. If you are bringing your child to the hospital with a fever or other signs of infection, it is a good idea to pack a bag for yourself and your child just in case you have an overnight stay.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

ATTENTION: If you speak another language, assistance services, free of charge, are available to you. Call 1-866-278-5833 (TTY: 1-901-595-1040).

ATENCIÓN: si habla español, tiene a su disposición servicios gratuitos de asistencia lingüística. Llame al 1-866-278-5833 (TTY: 1-901-595-1040).

تنبيه: إذا كنت تتحدث باللغة العربية فيمكنك الاستعانة بخدمات المساعدة اللغوية المتوفرة لك مجانا. .يرجى الاتصال بالرقم. 5833-278-866-1  (الهاتف النصي: 1040-595-901-1).