Unilateral lung hyperlucency syndrome in children

　　First, Etiology

　　The causes of this syndrome are as described in the pathogenesis.

　　Second, Pathogenesis

　　The causes and mechanisms of this syndrome are still controversial.

　　1. Pulmonary infection

　　Pulmonary infection during childhood may be a potential cause of this syndrome, especially viral pneumonia (including adenovirus, respiratory syncytial virus) which has special significance. Reid reported 2 cases of children who developed unilateral lung hyperlucency after measles, and chest X-rays were performed before the measles, showing no abnormalities, thus proving that this syndrome is a result of postnatal infection. Some believe that pulmonary infection is not the main direct cause of this syndrome.

　　2. Congenital developmental abnormalities

　　Unilateral lung hyperlucency is also common in pulmonary artery abnormalities, most of which are pulmonary artery hypoplasia, and a very few are pulmonary artery agenesis. According to hemodynamic examinations of patients with unilateral lung hyperlucency, it was found that the pulmonary vessels on the affected side had varying degrees of increased resistance, which could cause most blood flow to the healthy side of the lung, resulting in a decrease in the functional circulation volume of the affected side of the lung, thus producing pulmonary artery hypoplasia. Raymond et al. reported 5 cases of acquired unilateral pulmonary artery hypoplasia, emphasizing that pneumonia in childhood is an important factor causing pulmonary artery hypoplasia.

　　3. Obstruction of the bronchus by an external object

　　This syndrome can also be caused by the obstruction of the unilateral bronchus by an external object (including bronchial secretions and foreign bodies), thus producing an X-ray change of unilateral lung hyperlucency. Margolin performed bronchoscopy on 4 cases of unilateral lung hyperlucency, of which 2 had a history of aspiration of foreign bodies, but no foreign bodies were found.

　　4. Compression of the unilateral bronchus by an external object

　　It can cause respiratory tract obstruction or blockage, and there may be differences in lung opacity on both sides, such as thoracic tumors or cysts, etc.

　　There may be a history of recurrent infection of the lung or bronchus. It is more common in children, and women are more susceptible. The left lung is more affected than the right lung. Generally, it only involves one side or one lobe of the lung, but it can also involve multiple lobes, segments, and even the opposite lung, and can be accompanied by other interstitial lesions. The possible cause is that different results are produced by the same infection during infancy, such as SJS caused by obliterative bronchiolitis at this site, while at another site, it presents as bronchiectasis, atelectasis, and SJS. The main clinical manifestations include recurrent cough, sputum, hemoptysis, wheezing, and dyspnea. Most symptoms are related to whether bronchiectasis is present. Symptoms are significantly milder in patients without bronchiectasis or with columnar bronchiectasis than in those with cystic bronchiectasis.

　　1. This syndrome is more common in children, with a higher incidence in males than in females. The clinical manifestations are extremely atypical, and there may be no自觉 symptoms, only found during physical examination. There may also be a history of repeated infections in the lung or bronchus, cough, sputum, occasional hemoptysis, the affected side percussion sound is tympanic, and the respiratory sound is reduced or disappeared during auscultation. Sometimes fine moist rales or scattered dry rales can be heard, and if the affected side is the left lung, the cardiac dullness border is reduced or disappeared; if the affected side is the right lung, the liver dullness border is lowered.

　　2. If it is due to the inhalation of foreign bodies, there are often typical histories, severe coughing, followed by vomiting and difficulty in breathing, and the symptoms gradually decrease or relieve after a while. Depending on the location of the foreign body, different symptoms appear. When unilateral lung abnormal transparency occurs, the foreign body is often located in the unilateral bronchus.

　　Actively prevent and treat respiratory tract infections and prevent the occurrence of respiratory foreign bodies. One of the effective methods to prevent upper respiratory tract infections in children is to improve the immunity of the respiratory tract and enhance the resistance of children to pathogens. The following measures can be taken.

　　1. Promote breastfeeding

　　Breast milk is the most ideal natural food for infants, containing various nutrients. Breast milk contains a large amount of immunoglobulins, immune cells, lysozyme, lactoferrin, etc., which help to enhance the anti-infection ability of infants. Especially the colostrum secreted in the first few days after delivery, which is rich in antibodies and trace elements, especially SIGA, helps to prevent respiratory and gastrointestinal infections. Therefore, children breastfed with breast milk generally have fewer colds and flu.

　　2. Physical exercise

　　Physical exercise is beneficial to enhance the physique of children and improve their defense ability against diseases.

　　1. X-ray examination

　　It is the main means of diagnosis for this syndrome. Chest X-ray films show that the entire lung on the affected side is hypertransparent or the hilum shadow is reduced, the pulmonary vascular texture is fine, sparse and (or) straightened, and during the inspection, the mediastinum and heart are slightly pushed to the healthy side during deep breathing, and the mediastinum moves to the affected side during deep inspiration, or the movement range of the diaphragm on the affected side is relatively limited, with a flat top and a lower position. Layered filming shows that the pulmonary vessels on the affected side are sparse, which is due to the compression of alveolar aeration.

　　2. Bronchography

　　Its manifestations vary with different etiologies. When unilateral lung hypertranslucency is caused by pulmonary vascular abnormalities, bronchial changes are widespread, with varying degrees and types of bronchial dilation, and the branches around the bronchial tree (5 to 6 levels and below 6 to 7 levels) are unfilled or deformed.

　　3. Angiography

　　In some cases, the diameter of the pulmonary artery on the affected side is narrow, and the surrounding filling is poor or completely unfilled.

　　1. South Almond and Pork Lung Soup

　　Ingredients: Almond has two types, sweet almond (South Almond) and bitter almond (North Almond). South almond is a kind of seed of the apricot tree, with sweet, flat and non-toxic properties. It contains amygdalin, fatty oil, sugar, protein, resin, lupine saponin and almond oil, etc., which is a nourishing and soothing lung-coughing medicine. Because it contains a relatively rich amount of fatty oil (more than 50%), it has a good moisturizing effect.

　　Pig's lung, sweet, flat, can treat lung deficiency cough, hemoptysis, and has the function of invigorating the lung.

　　Preparation: Rinse and clean a pig's lung repeatedly. Cut the pig's lung into slices, squeeze with hands to wash away the foam in the pig's lung trachea. Then choose 15 to 20 grams of sweet almond (note: it is necessary to choose sweet almond, not bitter almond), put them together in a pot, add water, and boil to taste.

　　Function: Can be used for dry cough caused by dry and cold weather in autumn and winter. In autumn and winter, lung Qi is not open, dry cough without phlegm, constipation, dry throat, etc., all have certain effects.

　　2. Dendrobium and Polygonatum Duck Soup

　　Ingredients: Dendrobium, usually referring to Dendrobium officinale, sweet, slightly cold, enters the lung and stomach meridians. Contains alkaloids, starch, and dendrobium saponin. It can nourish yin, clear the lung, nourish the stomach, produce juice, and relieve deficiency fever, treat dry cough.

　　Polygonatum, sweet, slightly cold, enters the lung and stomach meridians. Polygonatum is moist and contains verbascoside, verbascoside, kaempferol glycoside, quercetin glycoside, vitamin A, starch, and mucilage. It can nourish yin, moisten dryness, moisten intestines, and promote defecation.

　　Old duck, sweet, warm, non-toxic, enters the spleen, stomach, lung, and kidney meridians. Functions to nourish yin and blood.

　　Preparation: Choose one old duck (note: it is necessary to choose an old duck), remove feathers and internal organs, clean it. Then choose 30 to 50 grams of Dendrobium and Polygonatum, put them together in a pot, and simmer for more than an hour, then season to taste.

　　Function: Can treat lung dryness, dry cough, and is also effective for constipation caused by body weakness, dry intestines, and other conditions. It is also a very nourishing recipe.

　　1. Treatment

　　The treatment of this condition should focus on etiological treatment. If caused by infection, the main treatment is active anti-infection. If caused by a foreign body, it is necessary to remove or clear the foreign body in a timely manner. Generally, those with不明显 symptoms often do not require surgical treatment. Katz followed up on one case for 15 years and there were no changes. Therefore, if the symptoms are not obvious, there is no need for surgical treatment.

　　2. Prognosis

　　The prognosis is related to the etiology and depends on the extent of the lesion and the condition. If caused by a foreign body, it can return to normal after the foreign body is removed; if caused by tracheal compression, the cause must be eliminated. Generally, unilateral lung opacity is abnormal and the prognosis is good.