Chest

Pleuropericardial and pulmonary manifestations are more common in adults aged 20 to 60 years, and are three to four times more frequent in men. In 59% of patients, there is no preceding history of diarrhea. Such manifestations are the result of a communication or extension of a hepatic abscess into the adjacent thoracic cavity, although isolated case reports suggest that the infection can be primary or by inhalation, with adverse bronchopulmonary manifestations. Typically, an abscess located high in the right lobe of the liver generates an inflammatory reaction in the lower thorax as a result of the subphrenic process.

Amebiasis within the chest may present as an acute condition when such an abscess ruptures through the diaphragm into the pleura, pericardium, lung, or a bronchus. There may be severe shock, dyspnea, cough, and tearing lower chest pain. Rupture into the pericardium can cause a fulminating pericarditis or acute tamponade and may resemble a myocardial infarction with sudden onset, dyspnea, shock, and cyanosis. In other patients, the initial clinical features suggest lower lobe pneumonia or pleural effusion. The pleural fluid may be either purulent or a transudate caused by reaction to the subdiaphragmatic abscess. Fistulization into a bronchus produces a creamy chocolate-colored expectoration.

The frequency of chest involvement depends to a certain extent on the location of the abscess within the liver: clearly, the closer to the diaphragm the more likely there will be perforation, a pleural exudate, or even pneumonia. In children, and occasionally in adults, the clinical picture of amebiasis may be that of a lung abscess presenting with purulent sputum, cough, pyrexia, and general malaise. These abscesses may be multiple, and can occur in any part of the lung. The liver need not be involved. The diagnosis may only be suspected when an apparently pyogenic lung abscess fails to respond to antibiotics; it may be confirmed by the discovery of amebae in the sputum.