Severe lung disease such as pneumonia is not always caused by bacterial flora. Parasites, fungi, drugs, immunodeficiency states, and allergic reactions can disrupt the homeostasis of the upper and lower respiratory tract. And in such cases, eosinophilic pneumonia develops.
Definition
Eosinophilic pneumonia is a pathological process in the lungs characterized by excessive accumulation of eosinophils in the alveoli. There are several types or variants of this pathology that can develop at any age.
Clinically, it is practically indistinguishable from a similar disease caused by bacteria, so the main emphasis in the diagnosis is on laboratory tests: complete blood count, sputum microscopy. In most cases, after determining the type of disease, therapy with steroid hormones of the adrenal cortex is started. This helps reduce the inflammatory response and relieve the symptoms of pneumonia. The prognosis for such patients is usually favorable.
History
Chroniceosinophilic pneumonia, the causes of which at that time were not known, was first described in the middle of the twentieth century, in 1969, by the doctor Harrington. He was not very shy, so he gave the disease his own name, and after publication, the entire scientific world began to call the new pathology Harrington's syndrome.
Prior to this historic article, eosinophilic pneumonia was known as a disease that develops in the lungs when infected with parasites or uncontrolled medication. Twenty years later, in 1989, the term "acute eosinophilic pneumonia" appeared in medicine.
Etiology
There are several factors under the influence of which eosinophilic pneumonia develops. Causes and symptoms are closely related. For example, acute forms of pneumonia are caused by smoking (both active and passive), allergies to drugs, or a decrease in the body's defenses in HIV or AIDS. If none of the causes fits, then the pneumonia is considered idiopathic.
Chronic eosinophilic pneumonia can be triggered by a fungal infection (aspergillosis, pneumomycosis), helminthic invasion (ascariasis, echinococcosis), long-term use of drugs that depress the immune system (glucocorticosteroids, cytostatics), chronic autoimmune connective tissue diseases (rheumatoid arthritis, sarcoma).
Eosinophils perform protective functions of the body, but since inflammation is a typical pathological process, whenexcessive and rapid flow, it can adversely affect the state of human he alth.
Pathogenesis
The etiological factor largely determines how eosinophilic pneumonia will develop. Causes, symptoms, treatment - it all depends on this. The cornerstone of this type of pneumonia is the accumulation of a large number of eosinophils in the tissues of the lungs. Many diseases, including eczema and bronchial asthma, are caused by an overreaction of the body with the release of biologically active substances.
Medications and other toxic substances change the reactivity of eosinophils, making them more susceptible. Anti-inflammatory substances, antibiotics, drugs cause allergies that lead to the development of secondary pneumonia. In addition, factors that provoke the appearance of a large number of eosinophils in tissues include cigarette smoke and chemical vapors.
Parasitic infections
Doctors identify three mechanisms for the development of pneumonia during parasitosis. The first is helminthic infestation in the lungs, the second is part of the life cycle of the worms, and the third is random shedding in the blood stream. To combat them, the body sends eosinophils. They should provoke the release of cytokines, prostaglandins, leukotrienes and other active substances for the elimination of worms. But instead they cause pneumonia.
Tapeworms, such as echinococcus and tapeworm, as well as the lung fluke, are specially introduced into the tissues of the lower respiratory tract. Stay in the lungsand access to atmospheric oxygen is essential for roundworms, intestinal acne, hookworms, and necators. Eosinophilic pneumonia, which is caused by the above pathogens, is otherwise called Loeffler's syndrome. Through the bloodstream, Trichinella eggs and schistosomes enter the lungs.
Clinic
As a rule, it is difficult for a therapist, pulmonologist or even an infectious disease specialist to answer the question at first glance, what kind of eosinophilic pneumonia does a patient have. Symptoms, even taking into account different etiologies, are very similar to each other. The patient complains of cough, fever, shortness of breath and sweating at night. A couple of weeks after the onset of a cough, if nothing is done, you can notice the symptoms of decompensated respiratory failure. In this case, the patient must be transferred to mechanical ventilation.
Chronic eosinophilic pneumonia progresses slowly over months. Patients lose weight, they develop shortness of breath, wheezing and cough, body temperature does not fall below subfebrile numbers. Sometimes the symptoms of the disease mimic bronchial asthma, making it difficult to make a diagnosis and choose the wrong treatment tactics.
Medical eosinophilic pneumonia creates many difficulties for diagnosis. Its symptoms, treatment and prevention strongly resemble aspirin asthma, which is misleading to the doctor. Parasitic infections have a specific prodrome that may suggest helminthic infestations.
Diagnosis
Since clinically eosinophilic pneumonia practically does not differ from other pneumonias, the diagnosis is made on the basis of laboratory and instrumental studies. In the general analysis of blood, eosinophilia is pronounced, when visualizing the lungs on fluoroscopy or computed tomography, characteristic pathological changes are noticeable. For confirmation, you can take a biopsy of lung tissue, as well as make a flush from the surface of the bronchi during bronchoscopy.
In order to establish an association with medication, exposure to chemically contaminated areas, or cancer, it is necessary to carefully study the patient's medical history, as well as collect a detailed anamnesis of life and illness. If, after all the research, it was still not possible to identify the cause, then the diagnosis is recorded as idiopathic eosinophilic pneumonia.
Be sure to indicate the degree of respiratory failure in the card. Within a week from the onset of the disease, its first signs appear:
- multiple lesions of the lung tissue;
- accumulation of fluid in the pleural cavity;
- leukocytosis and increased erythrocyte sedimentation rate in the general blood test;
- increase in the level of immunoglobulin E;- spirometry shows a decrease in the respiratory volume of the lungs.
Treatment
Even before a definitive diagnosis of eosinophilic pneumonia is made, treatment begins as soon as the patient sees a doctor.
If pneumonia is secondary, then it is necessary to treat the maindisease: tumor or helminthic invasion. This will help reduce lung symptoms and speed up recovery.
If the cause of the disease could not be identified, glucocorticosteroid therapy is prescribed. They well remove the inflammatory reaction, stabilize cell membranes, reduce the temperature. Remission is achieved quickly - on the third or fourth day. But the medication does not end there. The disappearance of symptoms does not mean that the disease is cured. Therefore, the patient takes corticosteroids for another month, with a gradual decrease in the dose until the moment when instrumental diagnostic methods do not confirm recovery.
The chronic form of the disease requires therapy for three months or more, even after the disappearance of clinical signs. Relapses of pneumonia are possible against the background of abrupt withdrawal of corticosteroids. In some cases, the patient may need to switch to mechanical ventilation.
Forecast
If eosinophilic pneumonia is a secondary disease on the background of a cancerous tumor or parasitosis, then the outcome of the disease depends on the course of the underlying pathology. Fatal outcome, subject to adequate and timely treatment, is unlikely.
Chronic eosinophilic pneumonia prone to recurrence on the background of withdrawal of glucocorticosteroids. Therefore, some patients take these drugs for life. But this situation also has a downside. Side effects from treatment, such as prednisolone, can severely impair quality of lifeperson. These include: peptic ulcer, osteoporosis, cushingoid, reduced immunity.
Epidemiology
Pneumonia caused by parasites is generally more common in regions where these pathogens are endemic. It can be the tropics, the Siberian taiga, the Mediterranean or the basin of some separate river.
Acute eosinophilic pneumonias can develop at any age, even in very young children, but are most common in middle-aged people: between twenty and forty years of age. The disease has some gender discrimination - men get sick more often than women, since the disease is caused by smoking. In modern medical literature, there are descriptions of the development of eosinophilic pneumonia after radiation therapy for breast cancer.
Eosinophilic pneumonia in dogs
Eosinophilic pneumonia also occurs in animals. The causes, symptoms, prevention of this disease are very similar to human ones. Similarly, the causes of the disease are: parasites in the lungs, fungi, allergies to pollen and insects, chemicals and drugs.
The dog has an uncontrolled immune response that causes eosinophils to infiltrate the lung tissue. The airiness of the lower sections decreases, pathogenic fungi develop there, which cause pneumonia. The animal dies from acidosis and hypoxia. Clinic similar to human: cough, shortness of breath, weakness, fever, lack of appetite, weight loss.
For diagnosis, a blood test, X-ray of the lungs, cytological examination of bronchoalveolarwashings, serological examination. The radiograph shows swelling of the lung tissue, the presence of cellular granulomas, an increase in the lymph nodes of the mediastinum and lung root, and an expansion of the shadow of the heart. After determining the etiology of eosinophilic pneumonia, the veterinarian prescribes a specific treatment aimed at eliminating the primary disease. The most effective are corticosteroids, in combination with antibiotics and bronchodilators. As a rule, animals remain on lifelong therapy.
