Isolated neutropenia in infants can occur in viral infections, autoimmune neutropenia of infancy, bone marrow suppression from a drug or toxin, hypersplenism, and passive placental transfer of maternal IgG.A bone marrow test can assist in diagnosis. The bone marrow usually shows early granulocyte precursors, but myelopoietic development stops ("arrests") at the promyelocyte and/or myelocyte stage, so that few maturing forms are seen. Neutrophil survival is normal. Treatment
Regular administration of exogenous granulocyte colony-stimulating factor (filgrastim) clinically improves neutrophil counts and immune function and is the mainstay of therapy, although this may increase risk for myelofibrosis and acute myeloid leukemia in the long term.Over 90% of SCN responds to treatment with granulocyte colony-stimulating factor (filgrastim), which has significantly improved survival. See also
Neutropenia
Cyclic neutropenia
GATA2 deficiency

References
Klein, Christoph (2011). "Genetic Defects in Severe Congenital Neutropenia: Emerging Insights into Life and Death of Human Neutrophil Granulocytes". Annual Review of Immunology. 29: 399–413. doi:10.1146/annurev-immunol-030409-101259. PMID 21219176. Further reading
Deotare UR, Patel PD, Parikh RP, Bhagat EA (January 2012). "Uncommon cause of recurrent infections". Indian J Med Paediatr Oncol. 33 (1): 51–3. doi:10.4103/0971-5851.96971. PMC 3385280. PMID 22754210. External links
Search for Neutropenia to see on-going projects at Orphanet
Severe Congenital Neutropenia (SCN) of Inherited Bone Marrow Failure Syndromes (IBMFS)
Severe congenital neutropenia at NIHs Office of Rare Diseases
Subungual exostoses are a type of non-cancerous bone tumor of the chondrogenic type, and consists of bone and cartilage. It usually projects from the upper surface of the big toe underlying the nailbed, giving rise to a painful swelling that destroys the nail. Subsequent ulceration and infection may occur.There is an association with trauma and infection. Diagnosis involves medical imaging to exclude other similar conditions, particularly osteochondroma. X-ray appearance may reveal a bony protuberance attached to the top or side surface of a toe bone.Treatment is by surgical excision and is effective.More than half are under the age of 18 years and males are affected equally to females. Combined with bizarre parosteal osteochondromatous proliferation, they comprise <5% of cartilage tumors. Signs and symptoms
They tend to be painful due to the pressure applied to the nail bed and plate. They can involve destruction of the nail bed. These lesions are not true osteochondromas, rather it is a reactive cartilage metaplasia. The reason it occurs on the dorsal aspect is because the periosteum is loose dorsally but very tightly adherent volarly. Diagnosis
Diagnosis involves medical imaging.Differential diagnosis includes mainly bizarre parosteal osteochondromatous proliferation (BPOP), which is more irregular and tends to involve the middle of the finger or toe rather than the end near the nail. They are distinct from subungual osteochondroma. Treatment
Treatment is by surgical excision and is effective. Epidemiology
It tends to occur in children and adolescents. Combined with BPOP, they account for less than 5% of cartilage tumors.