4. PULMONARY HEMORRHAGE IN INFANCY
Multiplicity of causes, most will represent bleeding from
a primary lung problem.
Pulmonary hemosiderosis (PH): Probably the most common cause in this age group, however no good
epidemiologic data available. A study in Sweden estimated incidence of pulmonary
hemosiderosis at 0.24 cases per million population.
PH is a clinical syndrome and not a specific disease. Characteristic
triad of iron deficiency anemia, chronic or recurrent respiratory symptoms,
and patchy infiltrates on chest radiograms during symptomatic episodes.
In infants Heiner's syndrome is the most common cause, idiopathic PH is
seen less commonly. Other causes of PH are rarely the reason for PH in infants.
Heiner's Syndrome (PH with sensitivity to cow's milk): Usual presentation is by age 6 months, but first episode has occurred in children as old as 9 years. History of recurring respiratory symptoms, mostly cough and tachypnea, with or without fever. Laboratory investigations will reveal iron deficiency anemia and radiographic abnormalities. Chest radiograms are usually clear between episodes, and infiltrates clear fast (days to weeks). Diagnosis based on presence of milk precipitins in serum and demonstration of hemosiderin laden macrophages, which are only seen after lung parenchymal bleed. Since infants swallow respiratory secretions, macrophages of lung origin can be found in gastric aspirate. Bronchoscopy with bronchoalveolar lavage is definitive diagnostic procedure, hemosiderin laden alveolar macrophages in lavage fluid can be easily demonstrated. However, these children may be seen primarily because of anemia and will have stool guaiacs performed, which will be positive, and be wrongly diagnosed as having GI bleed. High index of suspicion is crucial to make correct diagnosis.
After a diagnosis of Heiner's syndrome is established, treatment is based on milk products avoidance, oral corticosteroids and close follow up. Relapses are usually related to inadvertent ingestion of foods with some content of milk protein, and this should be clearly established if there is a relapse. Prognosis is usually good if relapses do not occur. In some cases disappearance of milk sensitivity may occurre as the child gets older, however any re-challenge should be performed under close supervision.
Idiopathic PH (IPH): In those infants on whom milk precipitins in serum are not found and on whom no other cause for bleeding can be found, diagnosis should be that of Idiopathic PH. Few cases have been reported where an IgA or IgG subclass 4 deficiency was detected, however the possible etiologic role of this is not clear. Since precipitins are neither specific nor sensitive, it is worth to have these patients go through a trial of milk products-free diet. Treatment is similar to that followed by patients with Heiner's syndrome. It is not unusual to see that relapses are related to viral infections, so the family must be instructed to watch closely the child during any respiratory infections. Patients who fail to respond to corticosteroids can be tried on immunesuppresors such as cyclophosphamide and azathioprine. IVIG has also been tried with variable success. Prognosis is variable, usually good for those who show response to therapy. Most patients will experience recurrence of pulmonary bleeds and some will die during severe episodes. In addition, patients with multiple bleeds will develop lung scarring and fibrosis which will impair their lung function. Close follow-up and periodic reevaluation are important, since there have been cases of other autoimmune disorders that have presented early in life as IPH as their only manifestation for many years.
Congenital malformations: Less common cause of pulmonary
bleeding in infants. Bronchogenic cysts, particularly when infected, can
be the source of large bleeding. Thoracic gastroenteric cysts have gastric
mucosa and the ability to secerete acid, for this reason the cyst wall can
be eroded and the erosion can extend to adjacent bronchial walls, vessels
or lung parenchyma, resulting in massive bleeding.
Congenital airway hemangiomas: Usually will become symptomatic by age 6 months. However, the symptomatology
is mostly related to airway obstruction, but cases of massive bleeding from
an airway hemangioma have been reported.
Primary pulmonary malignancies or metastatic
lesions: Rarely the reason for pulmonary bleeding
in infants.
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Pulmonary Hemorrhage in Children and Adolescents