Myelofibrosis can also occur from granulomatous infections, Gaucher's disease, and radiotherapy. Neutropenia associated with common childhood viral diseases occurs during the first 1 to 2 days of illness and may persist for 3 to 8 days. It usually corresponds to a period of acute viremia and is related to virus-induced redistribution of neutrophils from the circulating to the marginal pool. Neutrophil sequestration may occur after viral tissue damage. Autoimmune neutropenias may be associated with the presence of circulating antineutrophil antibodies and may occur in isolation or with associated diseases.
Cyclic neutropenia is a rare congenital granulocytopoietic disorder.
It may be inherited in an autosomal dominant fashion and is characterized by irregular, periodic oscillations in the number of peripheral neutrophils. Splenomegaly is not present. Pneumonias and chronic periodontitis often occur. Patients whose neutropenia is secondary to acquired disorders of production arising from cancer or from chemotherapy are more likely to develop serious bacterial infections because their overall immune system is compromised. The integrity of the skin and mucous membranes, the vascular supply to tissue, and the nutritional status of the patient also influence the risk of infections in acute neutropenia.