Neutrophils are essential components of the haematopoietic and immune system, and quantitative or qualitative abnormalities of neutrophils can result in life-threatening infection. Neutropenia is a low neutrophil count and results from decreased production, accelerated utilisation, increased destruction, or a shift in compartments. A combination of these mechanisms may be present. Causes can be congenital or acquired. The most serious complication of neutropenia is infection, which can be fatal. The source is usually endogenous flora of the gut and mucosa (commonly Staphylococcus and gram-negative organisms). Fungal infections occur with increased frequency, but there is no increased risk of viral or parasitic infection. Common sites of infection include mucous membranes (gingivitis, stomatitis, perirectal abscesses), skin (cellulitis), and lungs (pneumonia).
Via Alfredo Corell