Acute upper respiratory tract infection in children

Brief introduction of acute upper respiratory tract infection in children Acute respiratory infections are usually divided into acute upper respiratory tract infections (acuteupperrespiratory infections) and acute lower respiratory tract infections (acute lower respiratory tract infections), acute upper respiratory tract infections (referred to as upper sense), the general term for acute inflammation from the nasal cavity to the throat, is the most common About 90% of infectious diseases are caused by viruses. Bacterial infections are often secondary to viral infections. They are the most common diseases in childhood. They are also commonly used in the diagnosis of "acute nasopharyngitis", "acute pharyngitis" and "acute tonsillitis". , collectively referred to as upper respiratory tract infection, referred to as "upper sense." Acute upper respiratory tract infections can occur all year round, with the highest incidence in winter and spring, often invading the adjacent organs such as the mouth, middle ear, eyes, and cervical lymph nodes. basic knowledge Proportion of the disease: 90% of infants and young children Susceptible people: children Mode of infection: respiratory transmission Complications: myocarditis, bronchitis, sepsis

Causes of acute upper respiratory tract infection in children

Virus infection (35%):

Virus-based, can account for more than 90% of the primary upper respiratory tract infection, mycoplasma and bacteria are less common, after the virus infection, the upper respiratory tract mucosa loses resistance, bacteria can take advantage of the virtual, and mixed infection.

Rhinovirus: There are more than 100 different serotypes. The coronavirus is isolated by special methods. Both are common pathogens. The infection symptoms are limited to the upper respiratory tract and mostly in the nose.

Parvovirus and ECHO virus: These viruses are small and belong to piccomavims, which often cause inflammation of the nasopharynx.

Influenza virus: three serotypes of A, B, and C. The type A can cause a pandemic due to the dramatic variation of its antigenic structure. It is estimated that every 10 to 15 years, the epidemic of type B is small. And the limitation, type C generally only causes epidemics, and the condition is mild. The above three types mainly cause upper sense in children's respiratory diseases, and can also cause laryngeal, tracheal, bronchial, bronchiolitis and pneumonia.

Parainfluenza virus: divided into 4 serotypes, type 1 is called "erythrocyte-adsorbed virus type 2" (HA2); type 2 is called "croup-like virus" type 1 (HA1), often causing bronchiolitis or pneumonia There are also frequent croups; type 3 is endemic, can occur all year round, is highly contagious, can cause bronchitis and pneumonia in infants, most of them can be infected within 1 year old; type 4 is also called M-25, less common It can cause upper respiratory tract infections in children and adults.

Respiratory syncytial virus: only one type, has strong pathogenicity to the respiratory tract of infants and young children, can cause a small epidemic. About 15% of infants within 1 year old develop bronchiolitis, and about 30% cause throat and trachea. Bronchitis and pneumonia, after the age of 2, the incidence of bronchiolitis decreased, after 5 years old, only showed a light upper sense, lower respiratory tract infection was significantly reduced, the above three viruses are mucinous viruses, in acute upper respiratory tract infections Parainfluenza viruses, respiratory syncytial virus and coronavirus are more common.

Adenovirus: There are 41 different serotypes that can cause different upper respiratory tract infections, such as nasopharyngitis, pharyngitis, pharyngeal-conjunctivitis, follicular conjunctivitis, and can also cause pneumonia epidemics, type 3,7 Adenovirus can persist in the upper respiratory tract gland and can cause fatal pneumonia. Adenovirus type 8 can easily cause epidemic keratoconjunctivitis in school-age children. Types 3, 7, and 11 can cause pharyngitis and conjunctivitis. In the summer of 1983, the pharyngeal conjunctival fever of type 3,7 was caused by swimming in Beijing.

Mycoplasma infection (10%):

Mycoplasma pneumoniae (also known as pneumoniae pneumoniae or pleuropneumoniae-like microorganisms (PPLO), not only causes pneumonia, but also can cause upper respiratory tract infections, pneumonia is more common in children aged 5 to 14 years old.

Bacterial infection (15%):

Common bacteria: only about 10% of primary upper respiratory tract infections. Secondary bacterial infections invading the upper respiratory tract are mostly beta-hemolytic streptococcus group A, pneumococcal, Haemophilus influenzae and staphylococcus, among which streptococci It often causes primary pharyngitis, which is one of the common bacteria in the nasopharynx. Sometimes it can develop pathogenic bacteria infection in the respiratory tract, and there is an increasing trend, but it is second to S. pneumoniae and influenza bacillus infection.

Resistance decreased (20%):

Malnutrition, lack of exercise or excessive fatigue, and children with allergies, due to reduced body defense, prone to upper respiratory tract infections, especially in indigestion, rickets and primary immunodeficiency or acquired acquired immune dysfunction Children with these infections often have severe symptoms. In the winter and spring seasons with more climate change, it is more likely to cause epidemics. It must be pointed out that the occurrence and development of upper respiratory tract infection depends not only on the type of pathogen invading, toxicity and quantity, but also Closely related to host defense function and environmental factors, such as residential congestion, air pollution, passive smoking, and indirect inhalation of smoke, can reduce the local defense ability of the respiratory tract, promote the growth and reproduction of pathogens, so strengthen exercise, improve nutritional status and environmental sanitation to prevent It is very important.

Pathogenesis

Because children's defense function is imperfect, they are prone to respiratory infections, the secretion of mucous glands in the respiratory tract is insufficient, and the ciliary movement is poor. Therefore, the physical non-immune defense function is worse than that of adults. The lack of secretory IgA production makes the airway susceptible to microbial invasion. Propagation of droplets containing viruses, mist droplets, or contaminated utensils, often when the body's resistance is reduced, such as cold, fatigue, rain, etc., viruses and/or bacteria that have existed or are invaded by the outside world. Rapid growth and reproduction, leading to infection, in addition, due to the presence of bronchial hyperresponsiveness, some infants and young children cause respiratory allergic diseases due to factors such as respiratory infections.

Prevention of acute upper respiratory tract infection in children

1. Active exercise, using physical factors to exercise physique is very important, such as frequent window sleep, outdoor activities and physical exercise are all positive methods, as long as perseverance, can enhance physical fitness and prevent upper respiratory tract infection.

2. Speaking of hygiene, avoiding the cause of the disease, too much dressing, room temperature is too low, the weather is suddenly changing, environmental pollution and passive smoking are the causes of upper respiratory tract infection.

3. Avoid cross-infection, wash hands after contact with patients, wear isolation gowns when necessary in general care institutions and hospitals. Isolation not only protects neighboring children, but also reduces complications in sick children. Ventilation should be carried out in the ward to maintain proper temperature. Humidity, timely disinfection of the patient's bed clothing, so as to avoid the spread of pathogens, in the family, adult patients should avoid contact with healthy children.

4. Drug prevention, card slow Shu, infant 5ml, children 10ml oral, 3 times / d, 3 ~ 6 months for a course of treatment, levamisole 2.5mg / (kg · d), 2 days a week, 3 months For a course of treatment, the traditional Chinese medicine Astragalus membranaceus 6~9g per day, even for 2 to 3 months, the above drugs have the effect of improving the body's cellular and humoral immune function, repeated application of upper respiratory tract infection can reduce the number of recurrences, Beijing Friendship Hospital pediatrics used Chinese medicine Jiawei Yupingfeng Powder (formula: raw scutellaria 9g, Atractylodes 6g, windproof 3g, raw oyster 9g, dried tangerine peel 6g, yam 9g, research into fine) 2 times / d, each time 3g, oral, through 3 years observation, think this The drug seems to improve the immunity of the weak child and reduce the incidence of repeated respiratory infections.

5. Vaccination, it is recently believed that the application of attenuated virus vaccine, by intranasal instillation and / or aerosol inhalation, can stimulate the secretion of secretory IgA on the mucosal surface of the nasal cavity and upper respiratory tract, thereby enhancing the respiratory tract's defense ability against infection, a large number Studies have shown that secretory IgA is more effective against respiratory infections than any serum antibody, and because of the large variety of enteroviruses and rhinoviruses, it is difficult to prevent it with vaccines.

Complications of acute upper respiratory tract infection in children Complications Myocarditis bronchitis sepsis

Acute upper respiratory tract infection can cause many complications if not treated in time. Acute myocarditis, bronchitis, pneumonia, etc. often occur in infants and young children. Longer children can have nephritis, rheumatic fever, sinusitis, etc. Complications are divided into three categories. :

1. Infection spreads to nearby organs: infection spreads from the nasopharynx to nearby organs, more common are acute conjunctivitis, sinusitis, stomatitis, laryngitis, otitis media and cervical lymphadenitis, others such as posterior pharyngeal abscess, around the tonsils Abscess, maxillary osteomyelitis, bronchitis and pneumonia.

2. The infection spreads to the whole body: the pathogen spreads to the whole body through the blood circulation, and when the bacterial infection is accompanied by sepsis, it can lead to purulent lesions, such as subcutaneous abscess, empyema, pericarditis, peritonitis, arthritis, osteomyelitis, meningitis, Brain abscess and urinary tract infections.

3. Allergic diseases: due to the effects of infection and allergic reactions on the body, rheumatic fever, nephritis, hepatitis, myocarditis, purpura, rheumatoid diseases and other connective tissue diseases may occur.

Symptoms of acute upper respiratory tract infection in children Common symptoms Runny nose, nausea, chills, tears, tonsils, congestion, sore throat, high fever, low fever, diarrhea, convulsions

The severity of the disease varies greatly. Generally, the older children are lighter, and the infants and young children are more severe.

1. Incubation period: mostly 2 to 3 days or a little longer.

2. Mildness: only nasal symptoms, such as nasal discharge, nasal congestion, sneezing, etc., may also have tears, mild cough or pharyngeal discomfort, can be cured naturally within 3 to 4 days, such as infection involving the nasopharynx, often Fever, sore throat, tonsillitis and lymphatic tissue congestion and hyperplasia of the posterior pharyngeal wall, sometimes lymph nodes can be slightly swollen, fever can last from 2 to 3 days to 1 week, often cause vomiting and diarrhea in infants and young children.

3. Severe illness: body temperature can reach 39 ~ 40 ° C or higher, accompanied by cold feeling, headache, general weakness, loss of appetite, sleep uneasiness, etc., because the nasopharyngeal secretions cause more frequent cough, pharyngeal reddish When herpes and ulcers occur, it is called herpetic pharyngitis. Sometimes redness and swelling affect the tonsils, follicular purulent exudate, sore throat and systemic symptoms, nasopharyngeal secretions from thin to thick, submandibular lymph nodes. Significantly swollen, tenderness is obvious, if the inflammation affects the sinus, middle ear or trachea, the corresponding symptoms occur, the systemic symptoms are also more serious, pay attention to febrile seizures and acute abdominal pain, and other diseases for differential diagnosis, acute upper respiratory tract infection High fever convulsions are more common in infants and young children. They occur within 1 day after onset, rarely repeated. Acute abdominal pain is sometimes very intense. It is mostly around the umbilicus. There is no tenderness. It occurs early and is mostly temporary, which may be related to peristalsis. It is also persistent, sometimes similar to the symptoms of appendicitis, mostly due to acute mesenteric lymphadenitis.

4. Acute tonsillitis: It is a part of acute pharyngitis. Its course and complications are not the same as acute pharyngitis. Therefore, it can be used as a disease alone or in pharyngitis. Sometimes it can be seen on the surface of tonsils. White exudate, soft ulcers and small ulcers on the posterior wall of the pharynx, bilateral buccal mucosa congestion accompanied by scattered bleeding, but the mucosal surface is smooth, can be identified with measles, caused by streptococcus, generally more than 2 years old, onset More systemic symptoms, high fever, cold feeling, vomiting, headache, abdominal pain, etc., later sore throat or light or heavy, difficulty swallowing, mostly diffuse redness of the tonsils or at the same time showing follicular purulent exudate, patients with red tongue Thick moss, such as treatment is not timely, prone to sinusitis, otitis media and cervical lymphadenitis.

5. Course of disease: The fever time of light cases varies from 1 to 2 days to 5 to 6 days, but the heavier ones can reach 1 to 2 weeks, and occasionally have low heat for several weeks. Because the lesions are not cleared, it takes longer. Time can be cured.

Examination of acute upper respiratory tract infection in children

an examination

1. Blood picture: The classification of white blood cell count has certain significance for distinguishing virus or bacterial infection. The white blood cell count of the former is normal or low, and the total number of white blood cells is mostly increased. The disease is mostly viral infection. Generally, white blood cells are low or in the normal range, but in The percentage of early white blood cells and neutrophils was higher; the total number of white blood cells increased during bacterial infection, and the number of severe cases was also reduced, but the percentage of neutrophils was still increased.

2. Blood biochemical examination.

3. Electrocardiogram: If necessary, do an electrocardiogram to determine if there is any myocardial damage.

4. X-ray examination: Do a chest X-ray examination to determine whether there is bronchitis or pneumonia.

Diagnosis and diagnosis of acute upper respiratory tract infection in children

diagnosis

The following aspects should be noted:

1. Epidemic situation: Understanding the prevalence of local diseases is helpful for diagnosis and differential diagnosis. When an acute upper respiratory tract infection occurs, not only the symptoms are similar, but the complications are also the same.

2. Clinical features: comprehensive physical examination to exclude other diseases, observation of the pharynx including tonsils, soft palate and posterior pharyngeal wall, such as tonsil and pharyngeal mucosa marked redness, lymphatic follicular hyperplasia of the posterior pharyngeal wall, acute upper respiratory tract infection in infants and young children It is often characterized by sudden high fever and even febrile seizures. At the same time, there are vomiting, diarrhea, etc. Longer children are mainly nasopharyngitis symptoms, which are close to adults, but often accompanied by abdominal pain.

3. Blood: fever is high, when the white blood cells are low, common acute viral upper respiratory tract infection should be considered, and influenza, measles, malaria, typhoid, tuberculosis, etc. should be excluded according to the local epidemic and the contact history of the children. When the white blood cells continue to increase Generally, bacterial infection is considered, but it can be as high as 15×10 ⁹ /L in the early stage of viral infection, but neutrophils rarely exceed 75%. When leukocytes are particularly high, bacterial pneumonia should be excluded, and infectious mononuclear cells should be increased. Symptoms and whooping cough, acute pharyngitis with rash, generalized lymphadenopathy and hepatosplenomegaly should be checked for abnormal lymphocytes, except for infectious mononucleosis.

Differential diagnosis

1. Acute infectious diseases: Diagnosis can be made according to clinical manifestations and signs, but some acute infectious diseases such as children's acute rash, measles, whooping cough, scarlet fever, epidemic meningitis, etc., prodromal symptoms are similar to acute upper respiratory tract infections, so Careful inquiry should be made about the medical history, pay attention to the local epidemic situation, combined with epidemiology, physical signs and observation of disease development to make timely diagnosis. For example, if there is a large membranous exudate on the tonsil or beyond the tonsil, the diphtheria should be carefully excluded. Streptococcal infection should be considered when there is purulent secretion. The bacteria are usually examined by pharyngeal smear and cultured if necessary.

2. Sepsis and meningitis: If there is a hemorrhagic rash at the same time as acute pharyngitis, sepsis and meningitis must be excluded.

3. Identification with the flu: The flu has a clear epidemiological history, and there are many systemic symptoms such as high fever, sore limbs, headache, etc., which may have a debilitating state. Generally, nasopharyngeal symptoms such as nasal secretions and cough are more common than systemic poisoning symptoms. .

4. Identification with digestive diseases: Acute upper respiratory tract infections in infants and young children often have gastrointestinal symptoms such as vomiting, abdominal pain, diarrhea, etc., which can be misdiagnosed as primary gastrointestinal disease, upper respiratory tract infection with abdominal pain, but due to aphids The commotion, caused by mesenteric lymphadenitis, needs to be differentiated from acute abdomen and acute appendicitis.

5. Allergic rhinitis: Some patients with "cold" do not have severe systemic symptoms, often sneezing, runny nose, pale edema of nasal mucosa, long course of disease and repeated attacks, allergic rhinitis should be considered, nasal swab smear During the examination, if you see eosinophilia, it can help diagnose the disease, which is more common in preschool and school age.

6. Infectious mononucleosis: acute pharyngitis with rash, systemic lymphadenopathy and hepatosplenomegaly should be checked for blood, such as white blood cells are particularly high, abnormal lymphocytes should be excluded, infectious mononucleosis should be excluded .

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