Neutropenia

Overview

Neutropenia is a condition in which the blood has fewer neutrophils than normal. Neutrophils are a type of white blood cell that forms the body's front line of defense against bacterial and fungal infections. When their numbers fall, the body is less able to fight off germs, so even minor infections can become serious quickly.

Neutropenia ranges from mild, causing little or no problem, to severe, which carries a high risk of dangerous infection. It can be temporary, such as after a course of chemotherapy, or long-lasting due to bone marrow or immune conditions. Because a fever in someone with severe neutropenia can signal a life-threatening infection, it is treated as a medical emergency. Understanding the cause and following infection-prevention measures are central to staying safe.

Symptoms

Neutropenia itself often causes no symptoms and may be found on a routine blood test. The main danger is infection, so symptoms usually come from infections that develop. These include:

• Fever, often the first and most important warning sign
• Chills or shaking
• Sore throat or mouth sores
• Skin redness, swelling, or sores that may have little pus because of the low white cells
• Cough or shortness of breath
• Burning with urination
• Feeling generally very unwell

In someone with neutropenia, a fever is a medical emergency. Seek urgent care immediately for a fever or signs of infection, as a serious infection can develop rapidly and the usual signs may be muted.

Causes

Neutropenia can result from reduced production of neutrophils, their increased destruction, or their use being faster than they can be made. Common causes include:

• Chemotherapy and radiation: a very common cause, as they suppress the bone marrow.
• Medications: certain antibiotics, anti-seizure drugs, and others can lower neutrophils.
• Infections: some viral and severe infections temporarily reduce neutrophils.
• Bone marrow disorders: such as aplastic anemia, leukemia, or myelodysplastic syndrome.
• Autoimmune conditions: in which the immune system destroys neutrophils.
• Vitamin deficiencies: such as low vitamin B12 or folate.
• Inherited conditions: rare genetic disorders present from childhood.

Risk Factors

Factors that increase the likelihood of neutropenia include:

• Cancer treatment with chemotherapy or radiation
• Taking medications known to lower white blood cell counts
• Bone marrow diseases such as leukemia or aplastic anemia
• Autoimmune conditions
• Certain chronic or severe infections
• Poor nutrition with deficiencies of B12 or folate
• A family history of inherited neutropenia

Diagnosis

Neutropenia is identified by a blood test, and further evaluation seeks the cause. Tests may include:

• Complete blood count (CBC): measures neutrophils and other blood cells; often repeated to confirm.
• Blood smear: a look at the cells under a microscope.
• Review of medications and recent infections.
• Vitamin and immune testing: to check for deficiencies or autoimmune causes.
• Bone marrow examination: in some cases, to assess how blood cells are being made and look for marrow disorders.

The degree of neutropenia helps determine how high the infection risk is and how aggressively to act.

Treatment

Treatment depends on the cause and severity, and focuses on preventing and treating infection. Approaches include:

• Treating infections promptly: antibiotics are started quickly, often in the hospital, for fever in severe neutropenia.
• Addressing the cause: stopping a responsible drug, treating an underlying infection, correcting vitamin deficiencies, or managing a marrow or immune disorder.
• Growth factor medications: drugs that stimulate the bone marrow to make more neutrophils, used in certain situations such as after chemotherapy.
• Infection-prevention measures: careful hygiene, avoiding sick contacts, and sometimes preventive medications.
• Monitoring: regular blood counts to track recovery.

Mild neutropenia may need only monitoring, while severe neutropenia requires careful precautions and rapid treatment of any infection.

Prevention

While neutropenia from a needed treatment cannot always be avoided, infections can often be prevented and risks reduced. Helpful steps include:

• Washing hands frequently and practicing good hygiene
• Avoiding close contact with people who are sick
• Taking care with food safety and avoiding high-risk foods when advised
• Keeping up with recommended vaccinations as directed by your care team
• Reporting any fever or signs of infection immediately
• Taking medications, including any preventive antibiotics or growth factors, exactly as prescribed

When to See a Doctor

See a doctor if a blood test shows a low neutrophil count, or if you have frequent or unusual infections. Understanding the cause guides how careful you need to be.

If you have neutropenia, treat a fever as a medical emergency and seek urgent care immediately. Also seek prompt care for chills, mouth sores, a spreading area of skin redness, cough or breathlessness, burning urination, or feeling severely unwell. In severe neutropenia, serious infections can progress rapidly and the usual warning signs may be reduced.

Related Topics

Frequently Asked Questions

References

1. National Cancer Institute (NCI). Neutropenia and Risk of Infection.
2. MedlinePlus, U.S. National Library of Medicine. Neutropenia.
3. Mayo Clinic. Neutropenia — Definition and causes.
4. Centers for Disease Control and Prevention (CDC). Preventing Infections in Cancer Patients.