Patient's question:
AgeDetailed medical condition and purpose of consultation: On the evening of December 31, I had a cough due to catching a cold. Starting from January 1, I felt lethargic, and that night I had a high fever of 39.5°C. On the 2nd, I went to see a doctor and received intravenous fluids. I was also prescribed oral Taren and Semilla Pinelliae. On the evening of the 3rd, I started coughing again. On the 4th, a lung infection was detected, and my temperature was 37.6°C. The doctor switched me to intravenous Azithromycin, along with oral Kestine and Broncholitin. On the 4th, my temperature was 37.3°C, and I continued the same medication. The doctor said it was a 5-day course. On the 5th, my fever subsided, and the doctor said, "Mycoplasma was positive" (based on lung sounds, he said). I was alarmed because my colleague's daughter is 6 years old, and she was also diagnosed with positive Mycoplasma last year.
Doctor's answer:
Hello, considering Mycoplasma pneumoniae pneumonia. Mycoplasma pneumoniae is the smallest microorganism capable of independent life, existing between bacteria and viruses, with a size of 200 nm. It is transmitted through respiratory secretions (such as saliva and nasal discharge) via the air, causing sporadic and small-scale respiratory infections. It is primarily seen in children and adolescents, but it is also not uncommon in adults, with higher prevalence during autumn and winter.Examination
(1) Chest X-ray: Characterized by increased pulmonary (interstitial markings) and various morphological infiltrates in the lung parenchyma, more common in the lower lobes. It can also appear as spot-like, patchy, or uniform hazy shadows. Approximately 1/5 of cases show a small amount of pleural effusion. Lung lesions exhibit diversity: in the early stages, interstitial pneumonia is observed, with increased and reticular shadows on the lungs, later developing into spot-like or uniform hazy shadows, deeper near the hilar region and more common in the lower lobes. About half are distributed in a single lobe or a single pulmonary segment, sometimes with extensive infiltration and consolidation. Children may show enlarged hilar lymph nodes. A small number of cases have a small amount of pleural effusion. The pneumonia typically resolves within 2–3 weeks, occasionally extending to 4–6 weeks.
(2) Pathological Examination: The isolation of Mycoplasma pneumoniae is difficult to apply widely and is of little help in early diagnosis. Sputum, nasal, and throat swabs can be cultured for Mycoplasma pneumoniae, but it takes about 3 weeks. Additionally, antisera can be used to inhibit its growth, and the lysis of red blood cells can confirm a negative culture.
(3) Serological Examination: A serum pathogen antibody titer >1:32 and a Streptococcus MG agglutination test with a titer ≥1:40 are considered positive. A four-fold increase in titer on two consecutive tests holds diagnostic value.