Idiopathic Pulmonary Fibrosis in Children

　　1. Etiology

　　The etiology of this disease is unknown, and it is generally believed to be related to genetic and immune factors. Some have considered that it may be related to viral and bacterial infections, inhalation of dust and gases, and drugs may be triggering factors. Currently, it is generally believed to be an immune abnormality, possibly an immune complex disease. Some believe it may belong to connective tissue disease and autoimmune disorders, but neither has been confirmed. The disease is also related to genetic factors, as some cases have a clear family history and can occur in twins.

　　2. Pathogenesis

　　The pathological features are diffuse alveolitis and pulmonary interstitial fibrosis. The typical histological changes are the proliferation and disordered arrangement of interstitial fibrous tissue and collagen tissue, destruction of alveolar structure, fusion into cysts, with the cyst walls composed of fibrous tissue and proliferative type II alveolar epithelial cells. Under the electron microscope, type I alveolar cells disappear, type II cells increase and proliferate, the alveolar capillary membrane thickens, and immune complexes and complement deposits are visible in the alveolar wall and interstitium. Smooth muscle proliferation in the bronchioles, thickening of the walls of small pulmonary arteries. The alveolar septum has infiltration of lymphocytes, plasma cells, monocytes, histiocytes, and a few neutrophils and eosinophils. The alveolar lumen has cellular and fibrous exudates, etc., showing features of alveolitis.

　　Weight loss, fatigue, decreased appetite, and pulmonary heart disease. Finally, it may develop into respiratory failure and right heart failure. Most patients die due to respiratory failure caused by secondary infections. Pulmonary fibrosis, pneumothorax, mediastinal and subcutaneous emphysema are common, often accompanied by secondary infections, and may ultimately lead to respiratory failure and right heart failure. Most patients die due to respiratory failure caused by secondary infections.

　　This condition can occur in children and adolescents, and it can be visible as early as in 4-month-old infants. The onset is often insidious. The course of the disease is usually acute if it occurs before 6 months of age, from 6 months to 2 years it can be either acute or chronic, and after 2 years it is mostly chronic. The clinical symptoms are commonly characterized by dry cough, which may be accompanied by blood-tinged sputum, shortness of breath, progressive dyspnea, worsening after activity, and cyanosis. Generally, there is no fever, but there may be weight loss, fatigue, decreased appetite, and pulmonary heart disease. Finally, it may develop into respiratory failure and right heart failure. Most patients die due to respiratory failure caused by secondary infections. Physical examination shows poor development in children, clear lung percussion, and fine crackling sounds at the base of the lungs, known as Velcho啰音, with明显的杵状指(趾). Laboratory tests such as electrocardiogram, pulmonary function tests, and chest X-rays can help diagnose complications such as pulmonary fibrosis, pneumothorax, mediastinal and subcutaneous emphysema, which are often accompanied by secondary infections, and may ultimately lead to respiratory failure and right heart failure. Most patients die due to respiratory failure caused by secondary infections.

　　The etiology of the disease is unknown, and it is generally believed to be related to genetic and immune factors. Therefore, there is currently no effective preventive method. Strengthen physical exercise, enhance disease resistance, and pay attention to keeping warm in winter. Pay attention to adjusting the diet to increase nutrition; smokers must quit smoking. Eat less spicy, fried, fried, and greasy foods: the diet should be light. Obesity patients should control the intake of fat. It is better to eat lean meat to control weight and achieve the purpose of removing phlegm and dampness. Spicy, fried and other foods, because they are easy to produce phlegm, lead to heat assisting evil, evil heat is blocked inside and not reached, and over time, it will cause the evil heat to ascend to the lung, and worsen the condition.

　　1. General examination

　　30% to 50% of patients may have positive rheumatoid factor and antinuclear antibody, some patients have an increased erythrocyte sedimentation rate, and there may be hypergammaglobulinemia, positive cryoglobulin. There is an increase in eosinophils.

　　2. Blood gas analysis

　　Early on, it is hypoxemia without hypercapnia, but late on, hypercapnia may occur. Hypoxemia is related to exertion or exercise, that is, hypoxemia worsens during exertion or exercise.

　　3. Pulmonary function test

　　It manifests as restrictive ventilatory impairment. All lung volume values decrease proportionally and significantly, such as vital capacity, functional residual capacity, and total lung capacity; lung compliance and diffusion function also decrease significantly, with the latter appearing early and having a high detection rate.

　　4. Bronchoalveolar lavage fluid

　　A large number of inflammatory cells can be seen in the bronchoalveolar lavage fluid, and there are relatively more mast cells.

　　5. Lung biopsy

　　Diagnosis can be confirmed. Thoracotomy or trans胸腔镜 lung biopsy is considered the "gold standard" for diagnosing the disease. To obtain representative lung specimens, at least biopsy at two different sites is required, avoiding the apical and middle lobes, and more often in the upper and lower lobes on the same side. Thoracotomy or trans胸腔镜 lung biopsy can more accurately distinguish the extent of inflammation and fibrosis. It has certain diagnostic value for determining the activity degree of alveolar inflammation and end-stage lung fibrosis. The histopathological manifestations are as follows: under the naked eye, early stage may be normal, but it can be seen that there are lymphocytes, plasma cells infiltration around the alveolar wall, alveoli and bronchial wall, and occasionally eosinophils infiltration; in the late stage, it presents a diffuse honeycomb-like change. Under low-power microscopy, there is an uneven distribution of normal lung tissue, interstitial inflammation, fibrosis, and honeycomb-like changes, with the most serious in the peripheral lung parenchyma. Interstitial inflammation is distributed in patches, including infiltration of lymphocytes and plasma cells in the alveolar septum, accompanied by proliferation of alveolar type II cells.

　　1. Rock Sugar and Lily Soup

　　60g of lily, 15g of fritillaria thunbergii. After washing the lily, tear it into pieces and put it in a pot with fritillaria thunbergii, add an appropriate amount of water, and simmer over low heat. Add rock sugar when it is almost cooked, and simmer until the lily is soft and can be eaten. This dish has the effects of moistening dryness, clearing fire, calming the mind, and nourishing the lungs, which is especially suitable for patients with pulmonary fibrosis who have symptoms such as dry cough, restlessness, and thirst.

　　2. Lily Decoction

　　Take 30g of lily, 9g of ophiopogon, 12g of mulberry leaf, 9g of apricot, 10g of honey-fried fuki, and boil them with water. This recipe has the effects of nourishing yin, removing exterior, moistening the lungs, and stopping cough, and can be used to treat frequent coughing, dry cough without phlegm, dry mouth and throat in patients with pulmonary fibrosis caused by colds.

　　3. Lily and Pear Soup

　　Ingredients: One pear, 100g lily, 150g rock sugar. Preparation: Remove the core of the pear and cut it into slices; boil the rock sugar with 4 cups of water over low heat; soak the lily in water for 30 minutes, then cook it in boiling water for 3 minutes and drain it; put the pear, lily, and rock sugar in a炖盅, simmer for 1 hour.

　　Effect: Treats dry and hot cough, nourishing yin and stopping cough with lily can nourish yin and transform dryness, supplement moisture to the skin, and is a good food supplement material.

　　1. Treatment

　　There is no specific treatment. The principle is to control infection, control the development of pulmonary fibrosis, and symptomatic treatment. Nebulized oxygen therapy is often used in the acute stage. Corticosteroids may be effective in early cases with no obvious fibrosis, which can alleviate some symptoms but cannot cure the disease completely. There are reports that cyclophosphamide and azathioprine, etc., are effective immunosuppressants, and some use antimalarial drugs (chloroquine) for treatment. Some people have tried collagenase inhibitor D-penicillamine for treatment, but no definite efficacy has been obtained. The prognosis of the disease is poor. Acute cases may die within a few months, progressive cases may die of respiratory failure and pulmonary heart disease within more than 2 years, and chronic cases may survive for more than 20 years. In recent years, lung transplantation has been considered for treatment abroad, but there is no definitive conclusion.

　　2. Prognosis

　　Poor prognosis, those with acute onset may die within a few months, those with progressive onset have a 2-year survival rate, and cases with chronic progression may survive for more than 20 years. Most death cases die of respiratory failure, and it is often exacerbated by acute infection.