Neutropenia - group of rare hereditary diseases with almost full absence in a blood of the neutrophils, found out constantly (constant neutropenias) or at regular intervals (periodic neutropenias). As a rule, illnesses are inherited weakly.

The pathogenesis of primary mechanisms of a neutropenia is studied insufficiently, infectious inflammatory processes are caused by a neutropenia.

Clinical picture - predilection to infections (as a rule, staphylococcal), a serious parodontosis since the childhood (the naked necks of a teeth, their shaking and abaissement). At the periodic form of illness - a fever and infections are strictly periodical and correspond to days of a neutropenia. In a blood almost completely there are no neutrophils, the number of eosinocytes and monocytes is raised. At the periodic form these changes proceed some days, arising through strictly certain intervals of time. The anemia, a thrombocytopenia are absent. In an osteal brain - breakage of maturing of neutrophils at a stage of a promyelocyte (less often than a myelocyte), a monocytosis (at children of often many promonocytes), an eosinophilia.