OVERVIEW
Pulmonary eosinophilia (PE), also known as eosinophilia, is a group of diseases characterized by increased eosinophils in the circulation or tissues, and its clinical manifestations are characterized by varying degrees of chest tightness, shortness of breath, malaise, low-grade fever, cough and wheezing, etc. There are patches, clouds of scattered or wandering infiltrating foci in the lungs on X-ray; The severity of systemic symptoms varies, and the course of the disease varies widely. Clinically, they can be divided into 5 categories: simple, chronic or prolonged, asthmatic, tropical, and pulmonary allergic vasculitis with granulomas.
Etiology
1. Simple pulmonary eosinophilia
Anaphylactic reactions are often caused by parasites as antigens. In addition, there are drug reactions such as PAS, aspirin, furotoxin, barbiturates, thiouracil, penicillin and sulfonamides. Inhalation of pollen, fungal spores can also cause.
2. Delayed pulmonary eosinophilia
The etiology is similar to that of simple pulmonary eosinophilia, with hookworms and roundworms being the most common parasites, furotoxin being the most common drug allergy, and sporotrichosis and brucellosis being the others.
3. Asthmatic pulmonary eosinophilia
It can be caused by Aspergillus, helminths, schistosomes and filarial infections. Can also be caused by pollen, organic dust, animal feathers, dander, drugs and other allergies.
4. Tropical eosinophilia
In 1943, Weingarten and others first found in India, and then in Africa, Southeast Asia and the southern part of China has also been found. The occurrence of this disease is closely related to filarial infection or allergy.
5. Pulmonary allergic vasculitis and granulomas
The cause of the disease is not known, and it is thought that allergy to serum, drugs (sulfonamides, thiouracil, penicillin, hemolytic streptococci, etc.) is associated with causing type III allergic reactions.
Symptoms
1. Simple pulmonary eosinophilia
Clinical manifestations are mild, mostly occasionally found in X-ray examination, only a slight cough, cough a small amount of mucous sputum, fatigue, chest tightness, occasional fever, mostly low fever, similar to cold.
2. Delayed pulmonary eosinophilia
It is more common in young and middle-aged people, and there are more females than males. Chronic onset, the symptoms are more serious than simple pulmonary eosinophilia, with fever, cough, asthma, fatigue, hemoptysis, hepatosplenomegaly, pleural effusion. Often accompanied by changes in lung function, ventilation and diffusion function are impaired, with hypoxemia, and even respiratory failure can occur, physical examination can be heard in the lungs fine wet rales.
3. Asthmatic pulmonary eosinophilia
This disease usually develops in adulthood and is more common in women. Acute attack cough, cough mucus sputum, accompanied by fever and malaise, sputum coughing out the symptoms of shortness of breath can be relieved. Mucus plugs embedded in the fine bronchial tubes can occur atelectasis. Obstruction of the distal bronchioles may cause secondary infection of the lungs, and bronchiectasis may develop over time. The disease is easy to recur, the duration of the disease varies, and is often prolonged.
4.Tropical eosinophilia
It occurs in tropical and subtropical areas. Slow onset, often with fever, fatigue, poor appetite, paroxysmal spasmodic dry cough, or cough a small amount of mucus sputum, or sputum with blood, the lungs can be heard rales and wet rales, liver and lymph nodes can be enlarged. The course of the disease is long and may last for months to years.
5. Pulmonary allergic vasculitis and granulomas
Clinical symptoms include fever, cough, coughing up blood and wheezing. In addition to pulmonary lesions, the kidneys, skin and nervous system are also involved, with corresponding signs and symptoms.
Examination
1. Blood tests
The proportion of eosinophils in the blood increases, often exceeding 20%. Eosinophils increase significantly and the total number of leukocytes increases. Microfilariae can be detected in the blood if the infection is caused by filarial worms.
2. Immunologic examination
Some patients have elevated serum lgE and lgG; those caused by filarial infection have positive serum complement binding test for filarial antigen; those caused by Aspergillus, immediate and delayed biphasic positive reaction can be seen in skin test for Aspergillus antigen.
3. Sputum examination
There are a lot of eosinophils in sputum, and some patients can find Aspergillus mycelium in sputum.
4. Fecal examination
If the infection is caused by intestinal parasites such as roundworm, hookworm, etc., parasite eggs can be detected.
5.X-ray examination
The two lung fields can see variable patchy, cloudy or nodular shadows. Some of them may also show enlarged hilar lymph nodes and bronchial dilatation.
Diagnosis
1. Routine blood tests may show a significant increase in eosinophils and an increase in the total number of white blood cells. Microfilariae can be detected in the blood if the infection is caused by filarial worms.
2. Immunologic examination shows that some patients have elevated serum lgE and lgG; the serum of those caused by filarial infection has a positive complement binding test for filarial antigens.
3. Sputum examination shows a large number of eosinophils in the sputum, and some of them can also find Aspergillus mycelium.
4. Routine stool examination may detect parasite eggs.
5. Imaging examination shows variable patchy, cloudy or nodular shadows in both lung fields. Some cases may show hilar lymph node enlargement and bronchiectasis.
Treatment
According to the different causes of the disease, appropriate treatment should be given. If there is cough and sputum, expectorant and cough suppressant can be given. Effective antibiotics should be given to those who are co-infected.