DEAR MAYO CLINIC: My 16-year-old granddaughter was recently diagnosed with a low white blood cell count after going to the ER twice with a migraine headache, vomiting and temporary loss of sight. What could cause a low white blood cell count in someone her age? I am worried it’s something serious and am wondering what other tests should be done.
ANSWER: Many diseases and conditions can lead to a low white blood cell count. It is difficult to say what the specific cause might be in your granddaughter’s situation without more information. It is unlikely that the low count is related to her migraine and other symptoms. It would be wise to do another blood test to see if the problem persists. Her doctor can then decide if she needs to be evaluated further.
Blood has a number of components. In addition to white blood cells, which fight infection, red blood cells carry oxygen and platelets help blood clot. Bone marrow, the spongy tissue inside bones, makes the blood cells.
There are several kinds of white blood cells. Neutrophils fight fungal and bacterial infections. Lymphocytes protect the body from viral infections. Monocytes help get rid of dead or damaged tissue and regulate the body’s immune response. Eosinophils are disease-fighting white blood cells. Basophils play a role in wound healing, infection and allergic reactions.
One of the most common causes of a low white blood cell count is a viral infection. These infections can sometimes temporarily disrupt the bone marrow’s production of blood cells, so blood cell counts drop. The counts typically rebound as the body recovers from the infection. For most people, there is no long-term effect from this temporary drop in blood cells.
Certain medications may also lead to a low white blood cell count because they can destroy white blood cells or damage the bone marrow. For example, taking antibiotics may sometimes cause an abnormal drop in neutrophils, a condition known as neutropenia. With that in mind, it would be useful to have your granddaughter’s doctor review any medications she is taking to see if they could be causing changes in her blood cell counts.
A variety of other conditions and disorders may lead to neutropenia, too. For an overview of this condition and more details about how it is diagnosed and treated, you can view a Mayo Clinic video.
The list of other possible causes for a drop in a person’s white blood cell count is long. Autoimmune disorders, congenital disorders that affect the way bone marrow works, disorders of the spleen, certain infectious diseases, cancer and parasitic diseases, among others, can all lead to low white blood cell counts.
A good next step for your granddaughter would be to have a complete blood count test done. This test measures the components in blood. The specific type of white blood cells that this test shows to be low in your granddaughter, as well as the results of the other blood component measurements may help shed light on what could be causing the decrease.
The other symptoms you mention — headache, loss of vision and vomiting — should also be addressed with a physical exam, a review of your granddaughter’s family and medical history and any additional tests her doctor recommends. Even if these symptoms are not related to the decrease in her white blood cell count, it is important to investigate and identify their underlying cause. — Carola Arndt, M.D., Pediatric Hematology/Oncology, Mayo Clinic, Rochester, Minn.