| disease | Pulmonary and Pleural Amebiasis |
It is a suppurative inflammation of the lungs and pleura caused by infection with Entamoeba histolytica. Hepatic amoebiasis often occurs in the right lower lobe, while hematogenous spread typically results in multiple lesions in both lungs.
bubble_chart Diagnosis
1. Medical history and symptoms:
There is often a history of diarrhea or purulent bloody stools. During the acute phase, symptoms such as fever, lack of strength, night sweating, and loss of appetite may occur. Some patients may experience cough, expectoration, chest pain, and in some cases, bloody sputum, hemoptysis, or chocolate-colored sputum. If the abscess ruptures into the pleural cavity, severe chest pain and difficulty breathing may occur, potentially leading to pleural shock.
2. Physical examination findings:
On the affected side of the chest, respiratory movement is weakened, with possible tenderness and percussion pain in the intercostal spaces. Local percussion may reveal dullness, diminished breath sounds, or rales. Signs of pleural effusion may also be present. Chronic patients may exhibit anemia, emaciation, and clubbing of fingers (toes).
3. Auxiliary examinations:
(1) White blood cell count and differential: Elevated during the acute phase, more pronounced after secondary infection. In chronic patients, the white blood cell count and differential may be normal or decreased, with possible reductions in red blood cells and increased erythrocyte sedimentation rate.
(2) Sputum and pleural fluid examination: Detection of amoebic protozoa or trophozoites can confirm the diagnosis.
(3) Serological tests: Indirect hemagglutination, indirect fluorescent antibody, enzyme-linked immunosorbent assay (ELISA), and counterimmunoelectrophoresis all show high sensitivity. Negative test results help exclude the disease.
(4) Chest X-ray: Typically shows large areas of increased density with surrounding hazy infiltrates. In abscess formation, fluid levels may appear within the abscess cavity, along with irregular abscess walls. Pleural amoebiasis manifests as pleural effusion, pyopneumothorax, or pleural thickening and adhesions.(5) Ultrasound examination: Aids in diagnosis and determining the location and volume of pleural fluid.
4. Differential diagnosis:
This disease must be distinguished from bacterial lung abscess, pneumonia, pulmonary subcutaneous nodules, and other types of empyema.
bubble_chart Treatment Measures
1. Acute cases of sexually transmitted disease should rest in bed. Those with fever require fluid replacement and should be given dispelling phlegm and antitussive drugs. If necessary, trypsin and normal saline can be used for aerosol inhalation to dilute sputum for easier expectoration. Analgesics may be used for severe chest pain.
2. Drug therapy:
Metronidazole (Flagyl) 0.4–0.8g, taken orally 3 times a day for 5–10 days as a course, and can be repeated if necessary. For severe cases, intravenous administration is required: an initial dose of 15mg/kg followed by 7.5mg/kg every 6 hours, dissolved in 250ml of 5% glucose for intravenous drip, with a course of 7–10 days. Alternatively, Entamidum 0.5g, taken orally 3 times a day for 10 days as a course, or Tinidazole 2g, taken orally once a day for 3 days as a course, may be used.
3. Pleural effusion or empyema:
Puncture and drainage of fluid (pus) or closed drainage for expelling pus should be performed. Metronidazole 0.5g can also be injected into the pleural cavity for local treatment.
Postural drainage should be performed for patients with lung abscess and excessive sputum. Antibiotics should be added in cases of concurrent bacterial infection. Surgical treatment may be considered under the following conditions: (1) failure of medical treatment; (2) chronic fibrotic lesions; (3) formation of bronchopleural fistula.
