Causes of low blood cell counts in children include leukemia, chemotherapy or radiation treatment, and lack of sufficient vitamin B-12 in the diet, states Children’s Health Network. An infection such as tuberculosis and mononucleosis or an autoimmune disease, including lupus, may be responsible for low blood cell count.
Other causes of low white blood cell count include anaplastic anemia, HIV or AIDS, and certain medications including antibiotics and diuretics, states Mayo Clinic. Hypersplenism or premature damage of blood cells by the spleen; malnutrition; Kostmann’s syndrome, a congenital condition characterized by low neutrophil production; and myelokathexis, which is a congenital condition characterized by failure of neutrophils to enter the bloodstream, may also result in low blood cell count.
Overwhelming infections that exhaust white blood cells at a faster rate than their production and drugs that damage the white blood cells or destroy bone marrow also result in low blood cell count, explains Mayo Clinic. Cancer or other conditions that destroy bone marrow and congenital conditions involving reduced bone marrow function cause low blood cell count.
A condition of an abnormally low number of white blood cell count is known as neutropenia, states Children’s Health Network. Since the work of white blood cells is to protect the body against infections, children with neutropenia are at high risk of getting infections because of the limited number of white blood cells to fight disease-causing germs.