Pediatric white blood cell disorders

Many factors can cause too few or too many white blood cells. Find out more about these conditions in children.

Update Date: 01.05.2025

Overview
Symptoms
Causes
Risk factors
Diagnosis
Treatment
Preparing for an appointment
Overview
Symptoms
Causes
Risk factors
Diagnosis
Treatment
Preparing for an appointment

Overview

Children with pediatric white blood cell disorders have too few or too many white blood cells. White blood cells, called leukocytes, are part of the immune system. They come from bone marrow and help fight infections. Several conditions can cause having too few or too many white blood cells.

A low white blood cell count, also called leukopenia, means having too few leukocytes in the blood. A long-term low white blood cell count raises the risk of infections.

A high white blood cell count, also called leukocytosis, means having too many leukocytes in the blood. This most often is from an infection.

Types

There are several types of white blood cells. Each has its own disease-fighting activity. These are the main types:

  • Neutrophils. More than half the body's white blood cells are neutrophils. Having too few neutrophils is called neutropenia (noo-troe-PEE-nee-uh). Neutrophils fight infections caused by bacteria or fungi.
  • Lymphocytes. Too few lymphocytes causes lymphocytopenia (lim-foe-sie-toe-PEE-nee-uh). Lymphocytes, also called T cells and B cells, mainly protect against viral infections.
  • Monocytes. These white cells help rid the body of dead or damaged tissue. And they help the body's immune response.
  • Eosinophils. Eosinophilia (e-o-sin-o-FIL-e-uh) is a having too many eosinophil cells. These cells help with swelling and irritation, called inflammation. They also help with parasites and allergies.
  • Basophils. This is the least common type of white blood cell. Basophils have a role in wound healing, asthma and allergic reactions.

Symptoms

Symptoms depend on the type of white blood cell and whether there are too few or too many of them. Symptoms might be those of infections, conditions in which the immune system attacks healthy tissues, called autoimmune conditions, allergies and certain cancers.

Causes

The cause of pediatric white blood cell disorders depends on the type of white blood cell that's affected.

Neutropenia

Cancer and conditions that damage bone marrow can cause this low neutrophil count. Certain medicines, infections and other conditions also can cause neutropenia.

Lymphocytopenia

Syndromes passed through families, known as inherited syndromes, can cause too few lymphocytes. Lymphocytopenia also is linked with infections, cancer and conditions in which the body attacks its own tissue, called autoimmune conditions. And it can be a side effect of some medicines or other treatments.

Monocyte disorders

Infections, cancer, autoimmune diseases and other conditions can cause a rise in the number of monocytes. Toxins, chemotherapy and other causes can result in too few monocytes.

Eosinophilia

Allergic reactions, skin conditions or infections with parasites are the most common causes of having too many eosinophil cells.

Basophilic disorders

Allergic reactions or infections can lower the number of basophils. Certain types of blood cancer and other conditions can raise the number of basophils.

Risk factors

The following factors can raise the risk of pediatric white blood cell disorders:

  • Family history.
  • Infections.
  • Cancer.
  • Allergies.
  • Conditions in which the body attacks its own cells, called autoimmune conditions.
  • Certain medicines.

Diagnosis

Diagnosis of pediatric white blood cell disorder involves a detailed medical history and physical exam. Blood tests are key to diagnosing pediatric white blood cell disorders. Your healthcare professional may order other tests depending on the suspected cause.

Treatment

Treatment depends on the type of condition caused by the high or low white blood cell count and the underlying cause. Treatment for infection might involve antibiotics or antiviral or antifungal medicines.

Preparing for an appointment

If your child has symptoms that worry you, make an appointment with your child's main healthcare professional. Here's some information to help you get ready for your appointment.

What you can do

Make a list of:

  • Your child's symptoms, including any that seem don't seem linked to the reason for your appointment, and when they began.
  • Key personal information, including major stresses, recent life changes and family medical history.
  • All medicines, vitamins or other supplements your child takes, including the dosages.
  • Questions to ask your child's healthcare professional.

For pediatric white blood cell disorders, you might ask:

  • What's the likely cause of my child's symptoms?
  • What are other possible causes?
  • What tests does my child need?
  • Is this condition likely to go away or to last?
  • What's the best course of action?
  • Are there restrictions my child needs to follow?
  • Should I take my child to a specialist?
  • Are there brochures or other printed material I can have? What websites do you suggest?

Be sure to ask all the questions you have.

What to expect from your doctor

Your child's healthcare professional may ask you questions, such as:

  • Does your child always have symptoms or do they come and go?
  • How bad are the symptoms?
  • What, if anything, seems to make the symptoms better?
  • What, if anything, seems to make the symptoms worse?

© 2025 Mayo Foundation for Medical Education and Research. All rights reserved. Terms of Use