Meanwhile, several subtypes of neutropenia exist which are rarer and chronic, including acquired (idiopathic) neutropenia, cyclic neutropenia, autoimmune neutropenia, and congenital neutropenia.Neutropenia that is developed in response to chemotherapy typically becomes evident in seven to fourteen days after treatment, this period is known as the Nadir. Conditions that indicate the presence of neutropenic fever are implanted devices; leukemia induction; the compromise of mucosal, mucociliary and cutaneous barriers; a rapid decline in absolute neutrophil count, duration of neutropenia >7–10 days, and other illnesses that exist in the patient.Signs of infection can be subtle. Fevers are a common and early observation. Sometimes overlooked is the presence of hypothermia, which can be present in sepsis. Physical examination and accessing the history and physical examination is focused on sites of infection. Indwelling line sites, areas of skin breakdown, sinuses, nasopharynx, bronchi and lungs, alimentary tract, and skin are assessed.The diagnosis of neutropenia is done via the low neutrophil count detection on a complete blood count. Generally, other investigations are required to arrive at the right diagnosis. When the diagnosis is uncertain, or serious causes are suspected, bone marrow biopsy may be necessary. A bone marrow biopsy can identify abnormalities in myelopoesis contributing to neutropenia such as the stage of arrest in the development of myeloid progenitor cells. Bone marrow biopsies can also be used to monitor the development of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) in patients with chronic neutropenia (especially in those with severe congenital neutropenia (SCN) which carries a higher risk of MDS and AML)).
An absolute neutrophil count less than 200 is also considered a medical emergency and almost always requires hospital admission and initiation of broad spectrum antibiotics with selection of specific antibiotics based on local resistance patterns.Precautions to avoid opportunistic infections in those with chronic neutropenia include maintaining proper soap and water hand hygiene, good dental hygiene and avoiding highly contaminated sources that may contain a large fungal reservoirs such as mulch, construction sites and bird or other animal waste.Neutropenia can be treated with the hematopoietic growth factor granulocyte-colony stimulating factor (G-CSF). These are cytokines that are present naturally in the body. The factors promote neutrophil recovery following anticancer therapy or in chronic neutropenia. Recombinant G-CSF factor preparations, such as filgrastim can be effective in people with congenital forms of neutropenia including severe congenital neutropenia and cyclic neutropenia; the amount needed (dosage) to stabilize the neutrophil count varies considerably (depending on the individuals condition). Guidelines for neutropenia regarding diet are currently being studied. Those who have chronic neutropenia and fail to respond to G-CSF or who have an increased risk of developing MDS or AML (due to increased dosage requirements of G-CSF or having abnormal precursor cells in the bone marrow)  often require hematopoietic stem cell transplantation as a treatment.Most cases of neonatal neutropenia are temporary. Antibiotic prophylaxis is not recommended because of the possibility of encouraging the development of multidrug-resistant bacterial strains.These are cytokines that are present naturally in the body.