Streptococcus pneumoniae pneumonia in children
Introduction
Introduction to pneumococcal pneumonia in children Streptococcus pneumonia (septococcus pneumonia) refers to acute lung inflammation caused by Streptococcus pneumoniae (formerly known as pneumococci). Streptococcus pneumoniae often causes inflammation in the lung lobe or lung segment, both of which are primary, 3 More than the age of children, more common, especially older children, so the age group's body defense capabilities gradually mature. It can limit the lesion to one lung lobe or one lung segment without spreading, so it is also called lobar pneumonia. It can happen occasionally in infants and young children. Because the immune function is not mature, the pathogens along the bronchus are formed to become small airway. Characteristic lesions (bronchial pneumonia), secondary pneumococcal pneumonia is more common in infants and young children, often secondary to viral pneumonia, here mainly describes lobar pneumonia. The disease can occur all year round, but in winter and spring, the incidence of sudden changes in climate. basic knowledge The proportion of illness: the probability of illness in infants and young children is 15% Susceptible people: young children Mode of infection: non-infectious Complications: empyema, lung abscess, myocarditis, pericarditis, cerebral palsy
Cause
Pediatric pneumococcal pneumonia
Bacterial infection (65%):
Streptococcus pneumoniae is a Gram-positive diplococcus, a type of streptococcus, an asymptomatic carrier of bacteria, which plays a more important role in the spread of infection than pneumonia patients. The disease is usually sporadic.
Environmental factors (35%):
In the collective care institutions, there are also prevalences. When the climate suddenly changes, the body's resistance is reduced, and the incidence is more. It is more common in winter and spring, and may be related to the prevalence of respiratory virus infection.
Pathogenesis
Streptococcus pneumoniae is a Gram-positive cocci, which is arranged in pairs, even in chains or in a single existence. The bacteria do not produce endotoxin, and the pathogenicity depends on the invasion of the capsule containing the high molecular polysaccharide to the tissue. Streptococcus pneumoniae has 86 different serotypes according to its capsule-specific polysaccharide antigen typing. The common domestic pathogenic Streptococcus pneumoniae type is 5,6,1,19,23,14,2,3. 7,8 and other types, children with pneumococcal pneumonia are caused by 3,6,14,19 and 23 types. Streptococcus pneumoniae is a normal flora of the nasopharynx. Only when the respiratory defense mechanism is impaired can it cause disease. When the child has upper respiratory tract virus infection, fatigue, cold and other inducement, the body's immunity declines, the pathogens take advantage of it, and the disease occurs in the alveoli. The primary pneumococcal pneumonia lesions are often distributed in leaves, segments or sub-segments. Secondary pneumococcal pneumonia is a change in bronchopneumonia.
Prevention
Pediatric pneumococcal pneumonia prevention
In some countries and regions, high-risk populations susceptible to pneumococcal infection (including children, especially those with sickle cell disease) are prone to trials of multivalent pneumococcal polysaccharide vaccines, which are considered effective and are still Continue to study.
Complication
Pediatric pneumococcal pneumonia complications Complications empyema, lung abscess, myocarditis, pericarditis, cerebral palsy
Patients without proper treatment may have empyema, lung abscess, myocarditis, pericarditis and toxic hepatitis, severe cases may be associated with septic shock, and even cerebral palsy due to cerebral edema.
Symptom
Pediatric pneumococcal pneumonia symptoms Common symptoms Repeated upper respiratory tract infections irritability, facial flushing, flushing, dryness, cough, shortness of breath, high fever, cold, appetite, nausea and vomiting
1. Symptoms: A few have prodromal symptoms, and the onset is sharp. The clinical manifestations of older children with pneumococcal pneumonia are similar to those of adults. They may have transient mild upper respiratory tract infection symptoms, followed by chills, sudden high fever, and body temperature up to 40. ~ 4l ° C, facial flushing or cyanosis, chest pain, loss of appetite, fatigue and irritability or lethargy, dry cough, shortness of breath up to 40 ~ 60 times / min, exhalation sputum, nose fan, collarbone, intercostal space and rib arch depression Etc., often lack of signs in the early stage, more than 2 to 3 days after the appearance of signs of lung consolidation, chest pain when breathing, so the child is more lying on the side of the disease, the first few days more cough is not heavy, no sputum, after the sputum can be rust Color, early vomiting, a small number of children have abdominal pain, sometimes misdiagnosed as appendicitis, children may have diarrhea, mild symptoms are conscious, a few children have headaches, neck stiffness and other meningeal irritation, severe cases can have convulsions, And the performance of toxic encephalopathy such as coma, often mistaken for central nervous system diseases, severe cases can be associated with septic shock, and even cerebral palsy due to cerebral edema, larger children can see herpes labialis .
2. Chest signs: only mild percussion dullness or respiratory sounds are weak in the early stage. After the lungs become solid on the 2nd to 3rd day of the disease, there are typical percussive dullness, tremor and tubeatic breath sounds, sometimes snoring, lung signs in There were fewer changes in the whole course of the disease, but the wetness of the recovery period increased. In a few cases, the abnormal signs of the chest were not seen. The diagnosis must be confirmed by X-ray examination.
3. Natural course: Most of the body temperature retreats on the 5th to 10th day of the disease course, which can be lowered by 4~5°C within 24h. When it is as low as 35°C, it can be seen in sweat and collapse. It is similar to the state of shock. After 1 to 2 days of fever, the lung signs disappeared about 1 week.
Examine
Examination of pneumococcal pneumonia in children
1. Peripheral blood: white blood cell count and neutrophils are significantly increased, reaching (15 ~ 40) × 109 / L, even (50 ~ 70) × 109 / L, mainly neutrophils, nuclear left Moved, visible poisoning particles, but there are also a small number of children with leukopenia, indicating a serious condition.
2. Pathogen examination: airway secretion, blood, pleural effusion culture can be obtained by Streptococcus pneumoniae, sputum direct smear staining microscopic examination, if Gram-positive, paired arrangement of diplococcus has diagnostic significance, sputum And the blood culture has the growth of Streptococcus pneumoniae, the diagnosis can be confirmed, but the positive rate is not high.
3. Serological examination: 10% to 30% of children with pneumococcal pneumonia have bacteremia, but due to the early application of antibiotics, the positive rate of domestic blood culture is very low. At present, the pathogenic diagnosis of pneumococcal pneumonia mostly passes serum. Methods, such as the determination of S. pneumoniae antigen in children's serum, urine or saliva, but some authors believe that this method can not distinguish S. pneumoniae infection and colonization, recently reported by measuring serum pneumolysin antibody Or contain a circulating immune complex against S. pneumoniae antibody for diagnosis, but in infants, the sensitivity is not enough, blood can be collected, urine samples are detected by CIE, LA, etc. to detect S. pneumoniae capsular antigen, with radioimmunoassay The bactericidal test and EIJSA method are used to determine the antibody of S. pneumoniae for the auxiliary diagnosis, and the C-reactive protein is often positive.
4. Others: In addition, microscopic protein can be seen in urine examination. Most of the children can produce S. pneumoniae in nasopharyngeal secretions, but the pathogenic significance is not certain. For example, blood culture or pleural effusion culture can be carried out before antibiotic application. It has certain diagnostic significance. The X-ray changes are not necessarily parallel with the clinical process. The actual lesions appear earlier than the lungs, but they are not completely dissipated several weeks after the clinical remission. The young children's consolidation lesions are not common. The pleural reaction is accompanied by exudation. In the early stage of X-ray examination, the lung texture is deepened or limited to a shallow shadow of a segment. Later, a large number of shadows are even and dense, occupying the whole lung lobe or a segment, and gradually dissipate after treatment. In a few cases, pleural effusion occurred, and most children disappeared after 3 to 4 weeks of onset.
Diagnosis
Diagnosis and diagnosis of pneumococcal pneumonia in children
Diagnostic criteria
1. Characteristics of medical history: All age groups can be sick, but the incidence of older children is more; most occur in winter, spring season or sudden changes in climate, often before the onset of cold, rain, hunger, fatigue or upper respiratory tract History of viral infection.
2. Clinical manifestations: can be diagnosed according to x-ray examination.
Differential diagnosis
1. Identification with other acute fever: such as early lack of cough and chest signs, easy to mix with other acute fever.
2. Toxic encephalopathy: a small number of children with headache, neck stiffness and other meningeal irritation, such as vomiting, headache, convulsions or convulsions and coma and other toxic encephalopathy, should be associated with central nervous system infectious diseases and poisonous bacteria difference, the right upper lobe can be found in time to stiff neck, often mistaken for central nervous system diseases, X-ray is urgently needed to determine the diagnosis.
3. Surgical acute abdomen: Some right lower lobe pneumonia can stimulate the diaphragm, abdominal pain and vomiting are obvious, and there may be abdominal muscle tension, tenderness, need to pay attention to the identification of acute abdomen such as appendicitis, abdominal cramps are often not limited, Abdominal breathing is not weakened, abdominal X-ray, B-ultrasound can help identify, sometimes should pay attention to the abdominal tenderness of children with pneumonia is not limited to the right lower abdomen, abdominal muscle spasm can disappear under gentle pressure, no deep lagging pain In addition, when suffering from lobar pneumonia, body temperature and total white blood cells are generally higher than acute appendicitis.
4. Bronchial tuberculosis with pulmonary segmental lesions: signs of bronchial tuberculosis with pulmonary segmental disease or caseous pneumonia and X-ray findings, similar to large-leaf pneumonia, but slow onset, long course, slow absorption of lesions, mostly upper lung And often have a history of close contact with tuberculosis, tuberculin test is strongly positive, not sensitive to penicillin, and anti-tuberculosis treatment is effective, sputum acid-fast staining to find tuberculosis can help identify.
5. Klebsiella pneumoniae pneumonia: clinical manifestations similar to pneumococcal pneumonia, but the disease is sticky and purulent, with more blood, typical brick red jelly, X-ray can have multiple cellular abscess Leaf clearance, sputum examination can be found Gram-negative bacilli, to help identify, in addition to other pathogen-induced pneumonia such as pneumonia pneumonia, mycoplasma pneumonia, relying on laboratory tests to identify.
