The clinical conditions of “wheezing bronchitis”, “bronchial asthma” and “capillary bronchitis” are relatively common, and they have similarities and characteristics that should be distinguished from each other.
A. Wheezing bronchitis
The incidence of this disease is high in infants and children, and in addition to the manifestations of bronchitis, it is also accompanied by symptoms of asthma, and has a tendency to recur, with the possibility of natural remission in most cases. From clinical and prognostic considerations, wheezing bronchitis is an independent disease.
2, the disease can be caused by a variety of causes and triggers, such as anatomical and physiological characteristics of infants and children, infection or other factors cause bronchial mucosa congestion, edema, secretions are not easy to cough up, stimulate smooth muscle to produce bronchospasm and cause wheezing.
3, its clinical characteristics: mostly seen in infants and young children under 3 years old, often with a history of eczema and other allergies; mostly in the upper respiratory tract infection 2 to 3 days after the emergence of wheezing dyspnea, nasal flapping, wheezing day light and night heavy, often aggravated when irritable crying, quiet time to reduce. The fever is often low → moderate, the lungs can be heard more in the coarse wet history of sound, not fixed, with wheezing; wheezing is generally no obvious episodes, non-sudden sudden stop, wheezing is very loud, but dyspnea is not obvious, generally no wheezing; there is a certain recurrence, mostly related to viral infection. Most have a good prognosis, with the number of recurrences decreasing with age and cured by 4-5 years of age. Some cases can develop into bronchial asthma after a few years.
The name of this disease has been abolished in many countries abroad, and it was not included in the 2004 routine of childhood asthma in China, nor was it mentioned in the training manual for physicians on asthma in children, so it seems that there is a tendency to abolish it in China.
II. Bronchial asthma
1. As the respiratory system of infants and children develops, the immune function matures and resistance increases, most asthmatic bronchitis wheezing symptoms will gradually relieve or even disappear, and only the presence of atopic constitution or other factors without appropriate intervention will develop into bronchial asthma.
2, bronchial asthma is a variety of factors caused by the allergic reaction disease. The factors that trigger bronchial asthma are many, and the common factors include the following.
(1) Various allergens: pathogens that cause infections and their toxins. Inhalants: usually inhaled from the respiratory tract, the most important allergens are dust mites, house dust, mold, polyvalent pollen (Artemisia, ragweed), feathers, etc. Food: mainly heterogeneous proteins, such as milk, eggs, fish and shrimp, spices, etc.
(2) Mental and genetic factors, as well as climate, drugs, etc.
3. The onset of disease is either acute or slow. Infants and children often have 1 to 2 days of upper respiratory tract infection before the onset of disease, similar to general bronchitis. In older children, the onset of the disease is more rapid, and mostly at night. During the attack, the child is irritable and has dyspnea, with difficulty in breathing, often unable to lie down, shrugging his shoulders and bending his back in a seated position, and having sitting-like dyspnea.
4. Clinical manifestations also vary according to the allergens that cause asthma attacks. In the case of upper respiratory tract infection, dry and wet rales can be heard in the chest, accompanied by fever and increased white blood cell count. If the attack is caused by inhalation allergens, it is usually accompanied by nasal itching, runny nose, sneezing, dry cough, and then wheezing. Most people with high sensitivity to food do not have fever and often have symptoms such as swelling of the lips and face, vomiting, abdominal pain, diarrhea and urticaria in addition to asthma symptoms, most of which appear a few minutes after eating. If the sensitivity to food is light, the symptoms occur more slowly, often only mild asthma or dyspnea.
5. Inter-episode symptoms At this time, although there is no respiratory distress and the performance is like normal children, they can still feel discomfort in the chest. Because the pathological factors that cause bronchial susceptibility still exist, an asthma attack can be triggered immediately by infection or exposure to external allergens, but most children’s symptoms can disappear completely and no croup can be heard in the lungs.
6. Asthma itself is a chronic disease, often with chronic recurrent attacks. Some children have perennial attacks, or are controlled by medications, but the remission period is very short, mostly as a result of unfavorable control of acute attacks or recurrent infections.
The initial symptom of some infants and children is recurrent or persistent cough, or wheezing during respiratory infections, which is often misdiagnosed as bronchitis, wheezing bronchitis or pneumonia, and therefore treatment with antibiotics or cough suppressants is ineffective, and anti-asthma medication is effective at this time. The name of the diagnosis is “infantile asthma”.
Asthma should be considered if the child has a “cold” that repeatedly progresses to the lower respiratory tract and continues to improve after more than 10 days of treatment with anti-asthmatic medication. Although there is a potential for overtreatment in these children, effective treatment with anti-allergic inflammatory drugs and bronchodilators is better than antibiotics for shortening or reducing wheezing episodes, so health professionals are encouraged to use the term “asthma” rather than other terms when describing recurrent virus-related wheezing in early childhood.
Currently, there are two types of wheezing in infants and children:
1. Atopic (e.g., eczema), in which wheezing symptoms often persist throughout childhood and into *.
2. Those without an atopic constitution or family history of atopy, with recurrent episodes of wheezing associated with acute respiratory viral infections, whose symptoms usually disappear by preschool age.
Regardless of the type of wheezing mentioned above, bronchial reactivity may be increased and atopic inflammation may occur in some cases. There is no definitive way to predict which children will have persistent wheezing. Since more than 80% of asthma starts before the age of 3 years, early intervention is necessary. Although there is a risk of overuse of anti-asthmatic drugs in some children, effective use of anti-allergic inflammatory drugs and bronchodilators is better than antibiotics for shortening or reducing wheezing episodes and is consistent with the principles of early diagnosis and management of asthma in children.
Allergic cough: Some children with asthma have atypical clinical manifestations, with recurrent cough as the only complaint, and have been diagnosed with “upper respiratory tract infection” or “bronchitis” and abused antibacterial drugs for a long time, but the symptoms persist. The diagnostic criteria are as follows.
(1) The disease can develop at any age in children, but is more common in preschoolers;
(2) Recurrent cough attacks for more than 1 month, characterized by nocturnal or early morning attacks and dry cough without sputum;
③No clinical signs of infection or long-term antibiotic application is ineffective;
④The use of wheezing drugs can relieve the coughing attacks.
Capillary bronchitis
1. This disease is most common in small infants within 1 year of age, with more onset in winter and spring. It also has dyspnea and wheezing sounds, but its onset is slow and bronchodilators have no significant effect.
2. The pathogen is respiratory syncytial virus and, to a lesser extent, parainfluenza virus type 3. However, at present, tracheitis can also produce specific IgE and participate in type I metaplasia
The first infant wheezing may be capillary bronchitis, while multiple wheezing at the age of 1 year is going to be able to be asthma, and if the treatment is effective according to asthma, it will help the diagnosis.
There is little difference between asthma or wheezing bronchitis in terms of pathogenesis, clinical manifestations and especially clinical treatment. If there is a difference, it is that wheezing bronchitis is more closely related to infection, manifesting itself as a first time or recurrence mostly closely related to infections of the respiratory tract, etc. In fact, when we consider infection as a trigger or environmental stimulus, it is not difficult to understand the bronchial hypersensitivity of asthma, and infection is nothing more than a common irritant and the most common factor, so that the two can be considered as one disease, as also described in the GINA Report.
The relationship between childhood asthma and capillary bronchitis is not as obvious as the first two. Admittedly, there is considerable research that suggests a clear correlation between capillary bronchitis and the development of asthma (22.1-53.2% of children are found to convert to bronchial asthma based on long-term follow-up), but it is not necessarily causal, and we can predict that asthma is likely to occur after capillary bronchitis, and that the use of inhaled surface hormones during capillary We can predict that asthma is likely to occur after trichotillomania, and the use of inhaled surface hormones during trichotillomania can reduce this possibility, but we have no definite indicator to predict that specific patient will develop asthma in the future; and after 2 episodes of wheezing bronchitis, if it occurs again we can diagnose asthma, obviously, there is far from such a relationship between trichotillomania and asthma.
Second, treatment
1.Asthmatic bronchitis
Capital pediatric disease research:Application of bronchodilators, short-term application, mainly in the acute phase to relieve symptoms; advocate the application of hormones, but not static or oral, but advocate nebulized inhalation, the course of treatment for not less than three months, if the effect is not good, to reverse to see if the diagnosis is established. If there is a clear cause should also be treated for the cause.
2.Bronchial asthma
Medication principles.
(1) To avoid contact with such allergens and triggering factors such as cold and exercise.
(2) In general cases, oral aminophylline tablets or aerosol inhalation of bronchodilators (commonly used β2 agonists) and glucocorticoids can be used to relieve the attack.
(3) In severe cases, aminophylline plus hydrocortisone (or methylprednisolone) can be used as a sedative, while wheezing (or Bolicam) and pramipexole aerosol inhalation can be used to relieve the attack.
(4) Long-term aerosol inhalation of glucocorticoids (pramipexole aerosol or co-cortisone).
(5) Immunomodulators: such as transfer factor, thymidine, levamisole, aprotinin, BCG.
(6) Can be treated with Chinese herbal medicine anti-croup.
3.Capillary bronchitis
The treatment of capillary bronchitis should firstly pay attention to supportive therapy, including oxygenation and rehydration. The child with severe disease should be monitored by electrocardiography, and 2-3 L/min humidified oxygen should be used in time to correct hypoxemia. Rehydration should be calculated and compensated for the cumulative loss and physiological maintenance of the child, but excessive rehydration causes water and sodium retention in the interstitial space of the lungs, dysregulation of alveolar blood flow exchange, and even abnormal secretion of vasopressin leading to increased airway obstruction. Therefore, in principle, the recommended rehydration volume is 2/3 of the physiological maintenance volume plus the cumulative loss. Multiple oral rehydration is recommended, but intravenous fluids should be given to children with nasal mucosal edema or obstruction by secretions or tracheotomy.
Adjunctive therapy is aimed at overcoming airway obstruction and includes chest physiotherapy to remove cellular debris and fibrin from the lungs, anti-infective medications to control airway inflammation, and bronchodilators to relieve smooth muscle tone if necessary. It is recommended to pat the back and aspirate sputum after nebulizer treatment, elevate the head and upper body if the wheezing is severe to reduce respiratory distress, and reduce oxygen consumption by appropriate sedation.
Nebulizer or hormone injection can inhibit inflammation by regulating leukotriene synthesis, which can improve symptoms in the short term and shorten hospitalization and duration of symptoms. Adverse effects caused by the use of hormones, such as secondary bacterial infections, are relatively rare. Glucocorticosteroids are used for severe asthma attacks or for those who cannot be controlled by other treatments, methylprednisolone 1~2 mg/(kg・d) can be administered intravenously within a few hours.
Bronchodilators can improve the condition of some children, but they cannot relax the smooth muscle of the central airway and have the potential to aggravate the risk of airway obstruction, so the indications must be strictly evaluated before use.
Theophylline is a central nervous system stimulant, which does not improve the condition of the hairy branch, but is helpful in children with respiratory failure or on ventilator therapy; ipratropium bromide is an anticholinergic, which has a synergistic effect with β2 agonists, but does not enhance the mechanical stress and passive expiratory flow rate in the hairy branch. β2 agonists can relax smooth muscle to partially relieve clinical symptoms, but the response to β2 agonists varies greatly among children. The response to β2 agonists varies widely among children.
Antiviral therapy, including intravenous ribavirin, has been shown to be effective for gross RSV. To be effective, ribavirin must be administered at the time of early RSV replication. Ribavirin may reduce RSV-sIgE and IgA levels in nasopharyngeal secretions, and ribavirin may slightly reduce the incidence of asthma and reduce respiratory hyperresponsiveness. Personally, I prefer nebulized inhalation.
The prophylactic measures include frequent hand washing in contact with infants, avoidance of populated environments, and avoidance of patients with respiratory infections, which are high-risk factors for RSV transmission. RSV-IVIG is effective against both subtypes A and B of RSV, but the dosage is high (15 mL/kg, to be injected once/month). Monoclonal antibodies are 50-100 times more effective than RSV-IVIG in preventing wheezing in high-risk infants and post-hairy, and the dosage is small and can be injected intramuscularly, but they are expensive and may cause mutations in RSV genes, so they should be used with clinical caution.