D. Diffuse alveolar hemorrhage
Discussion
Imaging results suggest a diagnosis of diffuse alveolar hemorrhage (DAH). DAH was confirmed with bronchoscopy with bronchoalveolar lavage showing frank blood in the airways and in the alveolar wash.
Pulmonary hemorrhage is due to bleeding from either the arterial or
bronchial pulmonary circulation. Bleeding from the pulmonary arterial
circulation, seen in DAH, is typically slow and insidious as the
hemorrhage is from a high-volume low-pressure system. In contrast,
bleeding from the bronchial circulation is typically rapid and of larger
volume as it originates from a low-volume high-pressure system.
Hemorrhage can be the result of inflammation or injury to the
arterioles, venules, or alveolar septal capillaries. The etiologies of
pulmonary hemorrhage are broad including infectious processes, aspirated
foreign objects, bronchiectasis, vasculitis, congenital lung lesions,
congenital heart disease, pulmonary vascular disorders, pulmonary
masses, trauma, toxic inhalations, and coagulopathy or thrombosis
issues. Some cases, particularly of DAH, remain idiopathic.
Symptoms of DAH are classically cough, hemoptysis, fever, and
dyspnea. Importantly, hemoptysis can be absent in 33% of patients, such
as in our case presentation. The history should focus on timing and
volume of hemoptysis, fevers, choking events, drug exposures, and
extra-pulmonary manifestations such as hematuria or signs of
gastrointestinal bleeding. Physical examination should evaluate for
bruising, crepitus, telangiectasias, hemangiomas, digital clubbing, or
focal findings on pulmonary auscultation. Evaluation of the upper airway
to identify sources of bleeding from the nasopharynx and oropharynx is
essential. Chest radiographs can be non-specific with patchy or diffuse
opacities, necessitating a chest CT with angiography for further
diagnostic assessment. Laboratory evaluation should include a complete
blood count, coagulation studies, and an evaluation for infectious,
inflammatory, and rheumatologic processes. Bronchoscopy with
bronchoalveolar lavage is indicated to inspect the airways for a source
of bleeding, to collect cultures, assess for alveolar bleeding, and look
for hemosiderin-laden macrophages. Hemosiderin-laden macrophages appear
72 hours after the onset of bleeding and can persist for weeks. Lung
biopsy should be obtained in cases of persistent DAH if no cause of the
hemorrhage is identified.
Initial treatment for DAH includes supportive care, which can include
supplemental oxygen support, mechanical ventilation, and in extreme
cases, extracorporeal membrane oxygenation. High dose corticosteroids
are often utilized while awaiting a final diagnosis. Treatment depends
on the underlying etiology, but corticosteroids, immunosuppression, and
plasmapheresis are often utilized.
Our patient was admitted for further work-up; after an extensive
evaluation, the cause of her DAH remains unclear and she is diagnosed
with idiopathic pulmonary hemosiderosis.
Incorrect responses
A. Community acquired pneumonia (CAP) is an infection of the pulmonary parenchyma. CAP typically presents with fever, dyspnea, cough, and sputum production. Chest radiographs will show a pulmonary infiltrate, but not the diffuse pattern present in this case.
B. Iron deficiency anemia is the most common nutritional deficiency in children with a higher prevalence rate among children living in poverty. Prolonged iron deficiency can be the cause of marked anemia but should not produce changes on chest radiographs or CT.
C. Viral pneumonia can present with fever, dyspnea, cough, and sputum production just as CAP. Chest radiographs often show bilateral opacities. Viral infections can affect the bone marrow and cause anemia, but the severe anemia and diffuse infiltrates in this vignette would make viral pneumonia unlikely.
E. Pulmonary tuberculosis (TB) is a common presentation of TB in children. Symptoms can include cough, fever, weight loss or failure to thrive. Radiographic features of TB depend on the presentation; primary pulmonary, post-primary pulmonary, or miliary pulmonary TB. Miliary TB is caused by hematogenous spread of the infection. Chest radiographs show interstitial septal thickening and diffuse nodules, 1-3 mm in diameter, which are uniform in size and distribution. The opacities seen in our case show a diffuse alveolar process in contrast to a uniform nodular presentation expected in miliary TB.
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Susarla S.C. and Fan L.L. Diffuse Alveolar Hemorrhage Syndromes in Children. Current Opinion in Pedaitrics. 2007. 19(3):314-320.
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