Alveolar hemorrhage syndromes:
Acute idiopathic pulmonary hemorrhage of infancy

Symptoms
This diagnosis is characterized by the sudden onset of pulmonary haemorrhage in a previously healthy infant less than 1 year of age, in whom medical problems that might cause pulmonary hemorrhage, including physical abuse, have been ruled out. Severe cases will be in respiratory distress.

Diagnosis
Blood is often found in the nose and airways, though not always, with no evidence of gastrointestinal bleeding. Bronchoscopy shows the source of bleeding in the lung below the larynx and can originate from the upper or lower airways. Typical, severe cases present with respiratory distress, which may require mechanical ventilation, and chest X-ray or CT scan may show infiltrates. However, some infants present with sudden onset of pulmonary bleeding without distress, and their radiological studies may be unremarkable. Variation in severity might be related to the duration, severity, or nature of the etiologic agent(s) involved.

Treatment
The treatment for acute idiopathic pulmonary hemorrhage of infancy varies with the severity of the hemorrhage. Causes of the hemorrhage, like an underlying genetic abnormalities, immunodeficiency or blood clotting problems should be investigated. Some cases have been found in clusters which suggests possible environmental factors such as fungi, toxins, smoke or chemical pollutants. It is also important that the social circumstances are investigated in each case and that a careful search is undertaken for signs of physical abuse. It is important to note that it may be impossible to identify a causative agent.

Prognosis
The outcome of this diagnosis is dependent on the severity of the bleeding. If the bleeding is severe, the patient may require mechanical ventilation and the prognosis is worse. However, mild bleeding is not as severe.