Severe chronic neutropenia (SCN) is a rare blood disorder characterized by abnormally low levels of certain white blood cells (neutrophils) in the bloodstream (neutropenia) not explained by medication use, infections or another underlying health condition like blood cancers or systemic autoimmune diseases associated with neutropenia. Neutrophils play an essential role in fighting bacterial infections by surrounding and destroying invading bacteria (phagocytosis). Symptoms associated with severe chronic neutropenia include recurring fevers, mouth sores (ulcers), inflammation of the tissues that surround and support the teeth (periodontitis) and inflammation of the sinuses (sinusitis), throat (pharyngitis) and/or ear (otitis). Due to low levels of neutrophils, affected individuals may be more susceptible to recurring bacterial infections that, in some patients, may result in life-threatening complications. SCN may last for months or years and can affect both children and adults. Clinicians recognize three forms of the disorder: congenital, autoimmune and idiopathic neutropenia. The term idiopathic neutropenia is used when severe chronic neutropenia occurs for unknown reasons.
