Features of Mycoplasma pneumoniae pneumoniae pneumonia

Caused by Mycoplasma pneumoniae, it is more common in children aged 5~15 years, but in recent years, there have been increasing reports of JL infection in infants and young children, and it can be sporadic and prevalent.

Pathological changes are characterized by congestion, edema, thickening of the walls of the trachea, bronchi, and bronchioles of the lower respiratory tract, infiltration of monocytes and plasma cells, and obstruction of the airway by secretions and desquamation. There is also monocytic infiltration in the lung interstitium.

The onset is slow, and there may be general malaise, fatigue, headache, low-grade fever or moderate fever at the beginning of the disease, and the fever duration is 1~2 weeks.It is characterized by irritating dry cough, which is dry at first, and then turns into intractable severe cough, sometimes like whooping cough, coughing up mucus thick sputum, and even bloodshot. The cough lasts for a long time, up to 1~4 weeks, and is often accompanied by chest pain. Wheezing is more prominent in infants and young children, and it is sometimes difficult to distinguish it from respiratory syncytial virus pneumonia. Pulmonary signs are mild, with about one-third of cases showing no positive signs throughout the course of the disease. A few wet and dry rales may be heard locally in the lungs, and breath sounds may be reduced. In some cases, pleurisy may be complicated, and pleural effusion is mostly serous and occasionally bloody.

The white blood cell count is normal or high, and neutrophilia is increased. Erythrocyte sedimentation rate increases. A positive serum condensation test is helpful.

X-ray examination showed the following four changes: (1) the hilar shadow was more prominent; (2) Bronchopneumonia changes, mostly in the middle and lower fields of the right lung; (3) interstitial pneumonia changes, which radiate from the hilum to the medial band in the form of a network or cord, surrounded by small thin shadows or miliary shadows; (4) In some cases, there were large shadows, with uneven density and segmental distribution.A few are lobular shades, mostly in the lower lobes. Often, an old lesion is absorbed and a new lesion reappears.