Acquired Agranulocytosis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Acquired Agranulocytosis?
A primary care doctor often finds the problem first. A hematologist, a doctor who specializes in blood disorders, usually helps manage moderate to severe cases, and the two often work together. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Acquired agranulocytosis is a serious drop in one type of white blood cell called neutrophils, the cells that fight bacterial infections. The word "acquired" means a person is not born with the problem; instead, something later in life, most often a medicine, causes the drop. Without enough neutrophils, even small infections can become dangerous quickly.
Symptoms
The main sign is getting infections often or having infections that come on fast. Common problems include fever, sore throat, mouth sores, and feeling very tired. Because the body has few neutrophils to fight germs, these symptoms can appear suddenly and get worse quickly.
Causes and who gets it
Many medicines can cause acquired agranulocytosis, including some drugs used for thyroid problems, some mental health medicines, certain antibiotics, and some drugs used for the immune system. In some cases, the body attacks its own neutrophils. It is uncommon, can happen at any age, and is seen more often in older adults and in women.
How doctors diagnose it
Doctors start with a complete blood count, a simple blood test that measures the number of neutrophils. A very low neutrophil count confirms the diagnosis. Doctors will also review all medicines the patient takes and may run extra tests to rule out other blood problems.
Treatment
The first step is usually stopping any medicine that may be causing the problem. Infections are treated quickly with antibiotics, and some patients need hospital care until their counts recover. In some cases, doctors use medicines that help the bone marrow make more neutrophils.
When to see a doctor
See a doctor right away if you have a fever, sore throat, or mouth sores while taking a medicine known to affect white blood cells. Quick treatment matters because infections can get worse fast when neutrophils are low.
How a direct primary care or concierge doctor fits in
These doctors often have longer appointments and easier access, which helps when a patient needs quick answers about a fever or a medicine change. They can order blood counts, stop a suspect medicine when appropriate, and manage mild cases with close follow-up. If the neutrophil count is very low or the cause is unclear, they will refer the patient to a hematologist.
Common questions
Is acquired agranulocytosis the same as leukemia?
No. Agranulocytosis is a low count of one type of white blood cell. Leukemia is a cancer of blood-forming cells. Many cases of agranulocytosis are caused by medicines and improve after the medicine is stopped.
Will my blood counts go back to normal?
In many medicine-related cases, counts recover after the drug is stopped and infections are treated. Your doctor will repeat blood tests to track your progress.
Can I keep taking the medicine that caused it?
Doctors usually advise stopping the drug and avoiding it in the future, because taking it again could cause the same reaction. Always talk with your doctor before stopping or restarting any prescription.
How can I prevent infections while my count is low?
Doctors often suggest frequent handwashing, avoiding sick contacts, and good mouth care. Your doctor will give advice based on how low your count is.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
