<unk>  is a common pneumonia among patients with risk factors such as neurologic diseases, dysphagia, swallowing dysfunction, altered mental status, COPD, and hospitalization. Microaspiration and macroaspiration of different materials are the primary cause of<unk> . The mechanism behind damage of lung due to aspiration of depends on the content of aspirate and the response of lung tissue to the content. Chemical pneumonitis usually occurs following aspiration of materials that are toxic to pulmonary tissue. In case of oropharyngeal secretions the damage is due to bacteria infecting and inducing inflammation in lung tissues. Foreign body aspiration might present acutely with mechanical obstruction or chemical pneumonitis. Lipoid pneumonia is caused by aspiration of mineral oil when used for constipation treatment. Patients might present with acute chest pain, cough, fever, and sweating. Less common symptoms of<unk>  include fatigue, nausea and vomiting, diarrhea, and dyspnea. Chemical pneumonitis usually develop after aspiration of gastric acid and might present acutely within two hours. Rapid clinical recovery or worsening of respiratory distress and hypoxemia might happen. Bacterial infection following aspiration is slower that other community-acquired pneumonia and might be acute, subacute, or chronic. Complications of<unk>  include segmental or lobar pneumonia, bronchopneumonia, bronchiectasis, lung abscess, empyema, respiratory failure, bacteremia, and shock. Diagnosis of<unk>  is by history and symptoms following aspiration or in patients with risk factors. Chest x-ray is used to diagnose<unk> . Bronchoscopy is used to remove foreign body from the respiratory tract. Antibiotic therapy such as ampicillin-sulbactam, amoxicillin-clavulanate, or clindamycin for 7 days is required for chemical pneumonitis and bacterial infection. Supportive ventilation might be required in patients with respiratory failure following chemical pneumonitis. Clearing respiratory tract by suction is helpful to prevent the extent of pulmonary damage. Effective measures for the primary prevention of<unk>  include dietary habit changes, maintaining oral hygiene, postural maneuvers, and medications such as H2 antagonists, metoclopramide, mosapride, amantadine, or cilostazol.
Aspiration pneumonia
Bacterial pneumonia
Viral pneumonia
Pulmonary aspiration
Round pneumonia
Community-acquired pneumonia
Fungal pneumonia
Hospital-acquired pneumonia