Medical Guide for Mycoplasma Pneumonia (Introduction) http://www.mingyihui.net/article_435.html Mycoplasma pneumonia (Alternative names: Eaton pneumonia, primary atypical pneumonia)
What is mycoplasma pneumonia?
Mycoplasma pneumonia is a type of pneumonia caused by the pathogen Mycoplasma pneumoniae (MP), previously known as primary atypical pneumonia. The onset is slow, with symptoms including fever, paroxysmal irritating cough, and small amounts of mucus or mucus-pus sputum (occasionally blood-tinged). Pulmonary signs are often not prominent but can easily lead to extrapulmonary involvement in multiple systems, which may be life-threatening or fatal. It commonly affects children and adolescents, accounting for about 15% to 30% of all pneumonia cases, reaching up to 40% to 60% during epidemic years. Generally, the prognosis is good as it is a self-limiting disease.
What are the manifestations of mycoplasma pneumonia? Are there any special symptoms?
What are the early symptoms of mycoplasma pneumonia?
Clinical symptoms such as headache, fatigue, myalgia, nasopharyngeal lesions, cough, chest pain, purulent sputum, and blood-tinged sputum, along with pulmonary X-ray findings and laboratory tests like cold agglutination test, are helpful for diagnosis.
1. Medical history and symptoms:
The onset is relatively slow, with most cases presenting as pharyngitis and bronchitis, while 10% present as pneumonia. Symptoms include chills, fever, fatigue, headache, general malaise, irritating dry cough accompanied by sticky sputum, pus-like sputum, sometimes blood-tinged sputum. Severe cases may experience shortness of breath and chest pain when coughing intensely. Other symptoms may include nausea, anorexia, vomiting, diarrhea, joint pain, myocarditis, pericarditis, hepatitis, peripheral neuritis, meningitis, and skin maculopapular rash as extrapulmonary manifestations.
2. Physical examination findings:
Congestion and edema of the nasopharynx and conjunctiva, possible enlargement of cervical lymph nodes, rashes; chest signs are generally not prominent, fine crackles may be heard on auscultation of the lungs, occasionally pleural friction rubs and pleural effusion signs.
3. Auxiliary examinations:
(a) Chest X-ray: Increased lung markings, multiple infiltrative forms in lung parenchyma, more common in lower lobes, also seen as spot-like, patchy or uniformly blurred shadows. About one-fifth of cases have small pleural effusions.
(b) Pathogenicity tests: Isolation of Mycoplasma pneumoniae is difficult to apply widely and not helpful for early diagnosis.
(c) Serological tests: Serum pathogen antibody titer >1:32, Streptococcus MG agglutination test with titer 1:40 considered positive, a fourfold or greater increase in two consecutive tests has diagnostic value. Indirect serum test >1:32, indirect fluorescence test >1:66, indirect immunofluorescence anti-Mycoplasma pneumoniae IgG >1:16, anti-Mycoplasma pneumoniae IgM >1:8, affinity enzyme-linked immunosorbent assay can directly detect Mycoplasma pneumoniae antigens, results available within 24 hours, all having diagnostic significance.
Pulmonary lesions appear as patchy or confluent bronchopneumonia or interstitial pneumonia, accompanied by acute bronchitis. Alveoli may contain a small amount of exudate, focal atelectasis, consolidation, and emphysema may occur. Alveolar walls and septa have neutrophil and large mononuclear cell infiltration. Bronchial mucosal cells may undergo necrosis and desquamation with neutrophil infiltration. Pleura may exhibit fibrin exudation and slight fluid accumulation.
Incubation period is 2-3 weeks, onset is slow, approximately one-third of cases are asymptomatic. Manifestations include tracheobronchitis, pneumonia, otitis media, etc., with pneumonia being the most severe. Initial symptoms include fatigue, headache, sore throat, chills, fever, muscle pain, loss of appetite, nausea, and vomiting, with significant headache. Fever varies, possibly reaching up to 39°C. After 2-3 days, obvious respiratory symptoms such as paroxysmal irritating cough, small amounts of sticky or mucus-pus sputum, sometimes blood-tinged sputum, appear. Fever may last 2-3 weeks. Even after the temperature returns to normal, coughing may persist, accompanied by substernal pain but without chest pain.
Physical examination shows mild nasal congestion, rhinorrhea, moderate pharyngeal congestion. Ear drums often show congestion, with about 15% having tympanitis. Cervical lymph nodes may swell. In some cases, maculopapular rashes, erythema, or lip herpes may appear. Generally, the chest lacks significant abnormal physical signs; about half may hear dry or wet rales, and approximately 10%-15% of cases may develop small pleural effusions.
Generally, the condition is mild, though sometimes it can be severe, rarely leading to death. Fever lasts from 3 days to 2 weeks, coughing may extend up to around 6 weeks. About 10% may relapse, pneumonia occurs in the same lobe or different lobes, and in a few patients, red blood cell cold agglutinin titer exceeds 1:500. Significant intravascular hemolysis may occur, often during fever subsiding, or after exposure to cold.
A very small number of cases may be accompanied by central nervous system symptoms such as meningitis, meningoencephalitis, polyradiculoneuritis, or even mental disorders. Hemorrhagic tympanitis, gastroenteritis, arthritis, thrombocytopenic purpura, hemolytic anemia, pericarditis, myocarditis, and hepatitis have also been observed.
After understanding the manifestations of mycoplasma pneumonia, what should we do and what tests should we perform? http://www.mingyihui.net/article_435.html