The Infectious and Noninfectious Etiology, Clinical Picture and Outcome of Neutropenia in Immunocompetent Hospitalized Children.

BACKGROUND

Acquired neutropenia in immunocompetent children is common, and its differential diagnosis ranges from benign causes to life-threatening diseases. We described the etiology, clinical picture and outcome of new-onset neutropenia in immunocompetent children assessed in the emergency department and hospitalized at our medical center.

METHODS

Previously healthy children admitted with neutropenia (absolute neutrophil count <1.5 × 10(9)/L) were included. Serious bacterial infections were defined as culture-positive blood, urine, cerebrospinal fluid, articular fluid or stool infections, pneumonia, Brucellosis and Rickettsiosis.

RESULTS

A total of 601 patients (5 days-202 months old) were enrolled; 3 (0.5%), 48 (8%), 165 (27.5%) and 385 (64%) had absolute neutrophil counts <0.2, 0.2-0.5, 0.5-1.0 and 1.0-1.5 × 10(9)/L, respectively. Associated leukopenia and thrombocytopenia were diagnosed in 186 (39%) and 71 (11.8%) patients. Three hundred sixteen of 601 (52.6%) and 519 of 601 (86.4%) were <2 or 36 months of age, respectively. Fever at admission was present in 27.6% patients. Serious bacterial infections were diagnosed in 106 (17.6%) patients. Brucellosis and rickettsiosis were diagnosed in 8 of 52 (15.4%) and 9 of 39 (23.1%) tests obtained. Respiratory syncytial virus was diagnosed in 17 of 33 (51.5%) nasal washes. An infectious etiology was determined in 171 (28.5%) patients. Acute leukemia was diagnosed in 6 patients. A significant correlation was found between resolution of neutropenia and patient age, infectious etiology and severity of neutropenia.

CONCLUSIONS

(1) Severe neutropenia was rare; (2) More than half of patients were <2 months of age; (3) An infectious etiology was diagnosed in a high number of patients, and serious bacterial infections were frequent and (4) Brucella spp. and rickettsial infections were frequent etiologies associated with neutropenia in our setting.