After knowing the manifestations of mycoplasma pneumonia, then how should we carry out the necessary examinations?
1. Blood Profile: The total white blood cell count is often within the normal range but occasionally can increase. 25% of patients have white blood cells exceeding 10.0x10^9/L, a few can reach (25.0～56.0)x10^9/L. Classification shows a slight increase in neutrophils or eosinophils. Thrombocytopenia may occur. The direct Coombs test may be positive. Erythrocyte sedimentation rate can accelerate in the early stages of the disease.
2. Culture Method: Due to Mycoplasma pneumoniae's high nutritional requirements and slow growth, observation for 10～30 days or longer is required, which provides little help for clinical diagnosis. Currently, abroad, the Hayflied medium recommended by the U.S. Centers for Disease Control (CDC) is still used, while domestically, the medium based on Martin’s medium or pig lung digest developed by the Capital Institute of Pediatrics is commonly used.
3. Serological Methods:
- Complement Fixation Test: This is a widely-used serological diagnostic method for Mycoplasma pneumoniae infection. If the acute and convalescent double serum titers increase fourfold or a single serum titer reaches 1:32, it is judged as positive. Its sensitivity can reach 90%, specificity 94%, only showing positive during the initial infection, usually not showing a positive reaction during re-infection.
- Indirect Hemagglutination Test: Primarily detects IgM antibodies. Positivity appears after 7 days. Peaks between 10～30 days, gradually decreases between 12～26 weeks. Blood sampling during the acute phase should be done early; otherwise, it might be hard to measure the fourfold increased antibody. Specificity is not ideal, similar to the complement fixation test.
- Enzyme-Linked Immunosorbent Assay (ELISA): Used to detect IgM and IgG antibodies. The method is sensitive, highly specific, rapid, and economical, making it a practical and reliable means for diagnosing Mycoplasma pneumoniae infection. ELISA kits are now commercially available.
- Cold Agglutination Test: This is a non-specific test for diagnosing Mycoplasma pneumoniae infection, with 33%～76% of infected individuals being positive (titer 1:32). The higher the titer, the greater the likelihood of the disease. Positivity usually appears at the end of the first week or the beginning of the second week after onset, lasting about 2～4 months. This test can also show false positivity in pneumonia and respiratory infections caused by adenovirus, parainfluenza virus, etc., in infants and young children.
4. Nucleic Acid Hybridization Test: Detection of Mycoplasma pneumoniae using nucleic acid probe technology labeled with radioactive isotopes (such as 32P, 125I, etc.). Although this method has high sensitivity and specificity, it requires high conditions and involves the use of isotopes, making it difficult to apply clinically.
5. Polymerase Chain Reaction (PCR): Since 1992, this method has been used to check clinical specimens for Mycoplasma pneumoniae infection. From the comprehensive results, the positive rate of PCR detection is significantly higher than the culture method (sensitivity is 10～100 times higher than ordinary culture), and also significantly higher than serology and probe hybridization methods. It also has strong specificity, no cross-reaction with other mycoplasmas, and is not interfered by contamination from other oral bacteria. The required time is shorter, so adopting the PCR method can lead to an earlier accurate diagnosis, guiding clinical rational drug use. When symptoms appear in the central nervous system, rapid and reliable diagnosis becomes even more necessary. Since this method is quite sensitive, experimental operation should be particularly careful to avoid contamination.
X-ray examination of the lungs may reveal indistinct hazy shadows or uniformly consistent shadows. Near the hilum of the lung, they are denser and gradually become lighter outward, with unclear edges, usually not affecting the entire lobe. The vast majority involves one lobe, most commonly the lower lobe, with the left lower lobe being the most common, followed by the right lower lobe. About 20% of cases have a small amount of pleural effusion on the lateral view, around 10% show atelectasis, rarely pleurisy. Pulmonary lesions are usually absorbed within 2～3 weeks, complete absorption takes 4～6 weeks. About 30% of children have enlarged hilar lymph nodes.
After confirming the diagnosis through examination, what treatment should we adopt?
Precautions before treating Mycoplasma pneumonia:
Prevention:
In daily life, prevention of pediatric Mycoplasma pneumonia should be well managed. Experts remind that children should pay attention to physical exercise and frequently engage in outdoor activities. Indoor areas should be ventilated by opening windows, enhancing the body's cold resistance and adaptability to environmental temperature changes. Dress appropriately according to weather changes, avoiding contact with children suffering from respiratory infections. During the season when respiratory infectious diseases are prevalent, do not take children to public places. Nutrition should be reasonably adjusted, calcium supplements and vitamin AD should be given orally as early as possible, and sun exposure should be ensured. These measures can reduce the susceptibility factors of pediatric pneumonia and help prevent pneumonia. Vaccinations should be timely administered, and it should be ensured that children do not picky eat or have food preferences, ensuring adequate rest and sufficient sleep.
Traditional Chinese Medicine Treatment for Mycoplasma Pneumonia:
Traditional Chinese medicine treatment involves TCM differentiation. Pneumonia falls under the category of "lung heat wheezing cough" and "wind warmth invading the lung". Commonly used Chinese herbs include Ephedra, apricot kernel, raw gypsum, licorice, cold water stone, honeysuckle, forsythia, perilla seed, etc. For fever with sweating, add Scutellaria baicalensis or heavily use raw gypsum; for fever without sweating, add fresh reed root; for excessive phlegm with coughing and wheezing, add bamboo juice and radish seeds, etc.
Western Medicine Treatment for Mycoplasma Pneumonia:
1. General Treatment: Respiratory isolation, rest, providing sufficient hydration and nutrition. Symptomatic treatment: Avoid using salicylic acid drugs to prevent hemolysis. Generally, slowly acting antipyretic analgesics are selected, such as acetaminophen, calcium carbapirin, lysine pyridoxine, Bupleurum, etc. Physical cooling is auxiliary for high fever. Expectorant and antitussive. Clear nasal secretions to keep the airway open. Nebulization inhalation can be used if necessary.
2. Antibiotic Treatment: Clinically, erythromycin is the first choice, 30～50mg/(kg·d), divided into 4 doses orally, 1.5g/d for adults, divided into 3 doses orally, course of treatment 2～3 weeks. New macrolides like roxithromycin have fewer gastrointestinal side effects, higher fluid concentration, stronger cell penetration, longer half-life, smaller dosage, 5mg～10mg/(kg·d), divided into 2 doses orally. The new drug azithromycin capsules, first dose 10mg/(kg·d), then 5mg/(kg·d), once orally, 5 days as one course. Due to its long half-life, the drug effect can last for one week after discontinuation. There are also those who choose norfloxacin or ciprofloxacin 0.4g each time, twice daily, course of treatment 5～7 days.