Patient selection: adult with neutropenia
Step 1: If the patient is acutely ill and febrile, then admit the patient to the hospital, evaluate for infection and treat with appropriate antibiotics.
Step 2: Consider some possible causes.
(1) benign familial, cyclic or ethnic neutropenia (lifelong or family history)
(2) post-infectious (history of infection AND reverses with time)
(3) drug-related (history of exposure AND reverses on drug discontinuation)
(4) megaloblastic anemia (other cytopenias AND low folate or vitamin B12
Step 3: Perform a bone marrow with flow cytometry and cytogenetics to identify:
(1) myelodysplasia
(2) idiopathic neutropenia
(3) large granular lymphocytic leukemia (LGLL) or other infiltrative processes
(4) agranulocytosis (not part of original flow diagram)
Indications for more extensive workup:
(1) history of drug exposure AND neutropenia has not resolved after drug discontinuation
(2) history of infectious cause AND neutropenia has not resolved after recovery from infection
(3) other cytopenias AND normal folate, vitamin B12
(4) abnormal peripheral blood smear (not part of original flow diagnram)
(5) no other explanation for neutropenia
