Paediatric neutropoenia encompasses a vast range of congenital and acquired causes. Postinfectious neutropoenia represents the most common cause of acquired isolated neutropoenia.1 Neutropoenia following viral infections tend to be brief and usually resolve spontaneously without any serious side effects. These patients therefore do not have the same risk of sepsis and pulmonary complications as those patients with aplastic anaemia, congenital immunodeficiencies or those treated for cancer associated with neutropoenia. In the latter group pancytopoenia may be prolonged resulting in an increased risk of bacterial, viral, fungal and parasitic infections. Bone marrow failure occurs due to the disease process or following myelotoxic chemotherapy, irradiation and post haematopoeitic stem cell transplant (HSCT).

Advances in the treatment and supportive care for childhood cancer have resulted in the expected outcome being one of cure. However, in the intervening period the complications arising from neutropoenia may contribute to a significant morbidity and mortality. Pulmonary infiltrates make up a significant percentage of these complications.2 3 We present an overview of the many causes of pulmonary infiltrates in patients who are neutropoenic, and an approach to diagnosis and management.