Eosinophilia is an increase in the relative or absolute value of the level of eosinophilic blood cells. Eosinophilia is regarded as a manifestation of various diseases and transient pathological conditions of the body and for its recognition a prerequisite is to conduct laboratory research of peripheral blood.
In addition to changes in the cellular composition of peripheral blood with a predominance of eosinophilic cells, massive infiltration of various tissues and structures with eosinophils is observed in the patient's body. Thus, allergic rhinitis is accompanied by impregnation with the eosinophils of the mucous membrane of the nasal cavity, and in case of tumor lesions of pleural sheets in accumulated exudate, eosinophilic cells are also determined.
Under normal conditions, the number of eosinophilic blood cells should not exceed a threshold of 0.3 × 109 / L. But in the laboratory study of blood, more attention is paid to the percentage of eosinophils contained in relation to the total number of leukocytes, and this percentage should not exceed 10%.
Causes of eosinophilia
Due to the fact that eosinophilia is only a manifestation of various pathological conditions, the causes of its occurrence should be sought in the etiopathogenesis of the underlying disease, the manifestation of which it has become.
The main risk group for this pathology of the blood should include children of children with different degrees of allergic reaction from simple allergic rhinitis and seasonal pollinosis to severe form of Quincke edema and serum sickness. Patients, long suffering from a persistent form of bronchial asthma, have significant changes in the leukocyte blood formula and are characterized by high eosinophilia.
In connection with the rapid development of tourist recreation and visits to countries that are disadvantaged in relation to parasitic and helminthic invasions, an increasing number of patients with eosinophilia have signs of parasitic diseases (ascaridosis, schistosomiasis, malaria and others).
The predominant majority of dermatological diseases is accompanied by an increase in the number of eosinophils in the peripheral blood and such pathologies include eczema , herpetiform dermatitis and lichen.
Separately, we should consider different forms of pulmonary diseases, accompanied not only by the increase of eosinophilic blood cells in the flow of circulating blood, but also by the eosinophilic infiltration of the pulmonary parenchyma. Pulmonary eosinophilia has the features of the course of respiratory disorders and specific diagnostic signs, so patients with this pathology need an individual approach to the use of therapeutic measures.
A large group of patients with eosinophilia are cancer patients with diagnosed carcinomatosis of the stomach, thyroid cancer and malignant neoplasms of the pelvic organs.
The terminal stage of immunodeficiency diseases is manifested by significant changes in the formula of white blood, including an increase in the level of eosinophilic blood cells.
A prolonged course of autoimmune and rheumatic diseases in the form of rheumatoid arthritis , eosinophilic fasciitis and scleroderma, sooner or later provoke eosinophilia.
The so-called transient eosinophilia can provoke long-term administration of drugs of certain pharmacological groups, which include: antituberculosis drugs, antibacterial drugs of the penicillin group, sulfonamides.
Symptoms of eosinophilia
Eosinophilia does not have its own specific manifestations and is rather a laboratory sign, therefore its clinical symptomatology is characterized by a major disease, against which background changes in the content of eosinophils in the blood have occurred.
Thus, in reactive diseases of autoimmune origin, patients complain of progressive weight loss, not related to changes in dietary intake, short-term episodes of hectic-type fever attacks, persistent aching pain in the area of large and small joints that are not related to physical activity. Primary objective examination of the patient with eosinophilia of autoimmune genesis is accompanied by an increase in the parameters of the spleen and liver, signs of heart failure in the form of ascites, peripheral edema and an increase in the absolute cardiac dullness. Changes in the parameters of the blood test consist not only in the increase in eosinophilic blood cells, but also in the severity of anemia.
The clinical symptom complex of eosinophilia of parasitic origin is more extensive and the manifestations of intoxication syndrome in the form of a lack of appetite, nausea, febrile fever, dizziness and pronounced weakness appear to the fore. A characteristic manifestation of eosinophilia in this case is the appearance of muscle pain and arthralgia. In an objective examination of the patient, attention is drawn to the significant hepatosplenomegaly and widespread lymphadenopathy, which consists not only in the formation of conglomerates of enlarged lymph nodes of different locations, but also in severe pain when palpated.
The appearance in the patient with eosinophilia of a common urticaria rash, accompanied by severe itching and the formation of ulcers, supports the allergic nature of the disease.
The presence of signs of dysbacteriosis in the form of nausea and frequent episodes of vomiting, various degrees of upset of the stool and convulsive syndrome, should lead to the idea of eosinophilia appearing in a patient suffering from gastrointestinal tract diseases.
Forms of eosinophilia
The separation of eosinophilia into clinical types and forms is necessary to determine the tactics of conducting and treating a patient. This classification is based on the etiopathogenetic principle, that is, the form of eosinophilia is determined by the cause of its occurrence or localization of its manifestations.
Thus, eosinophilia of an allergic nature arises from the release of a large concentration of histamine and eosinophilic chemotoxic factor by mast cells and enhanced migration of eosinophilic cells to the epicenter of an allergic reaction. The mechanism of activation of the cytotoxic function of eosinophils is provoked by the presence of foreign microorganisms on the surface of the mucosa. The main diagnostic method in this situation is a smear on eosinophilia from the nasal cavity. An increase in the percentage of eosinophil cells in the smear is an absolute diagnostic criterion for allergic eosinophilia.
Eosinophilia of autoimmune genesis or eosinophilic syndrome is a diagnosis, the establishment of which is possible only by the elimination of all possible allergic diseases. For the diagnosis of "eosinophilic syndrome" must necessarily be the presence of a set of specific clinical and laboratory signs and the absence of symptoms of an allergic nature. The laboratory sign is a continuous progressive eosinophilia of more than 1.5 × 109 / L and anemia.
Clinical criteria for autoimmune eosinophilia is the appearance of hepatosplenomegaly, organic heart murmurs, congestive heart failure, diffuse and focal symptoms of brain damage, weight loss and febrile syndrome. This form of eosinophilia is more common in young people and is considered extremely unfavorable with respect to treatment. In childhood, the eosinophilic syndrome manifests itself as an isolated lesion of an organ, with the primary localization being the heart.
Eosinophilia, observed with limited inflammatory processes in certain structures and tissues, proceeds with some peculiarities. So, eosinophilic myositis is a volumetric neoplasm with a clear localization in a separate group of muscles, with a predominant lesion of the muscle fibers of the lower extremities. Muscle pain is accompanied by a febrile syndrome and persistent disability.
Eosinophilic fasciitis is similar to the clinical manifestations of scleroderma with the predominant lesion of the face and skin, but unlike scleroderma this pathology is characterized by a rapid progressing current and is well susceptible to hormonal therapy. With this form of eosinophilia, the detection of eosinophilic cells is possible not only in the peripheral blood, but also in the skin.
Eosinophilic gastroenteritis is a poorly understood pathology, as it is quite complex in diagnosis and does not have specific clinical manifestations that distinguish it from other diseases with intestinal damage. The only pathognomonic symptom of this form of eosinophilia is the discovery of Charcot-Leiden crystals in the patient's bowel movements.
Eosinophilic cystitis is a pathology of autoimmune nature and belongs to the category of "diagnosis of exclusion", that is, its establishment is possible only with the long absence of the effect of treatment and the inability to determine the etiopathogenetic factor of its occurrence. The increased number of eosinophilic cells in the circulating blood is combined with the accumulation of eosinophils in the mucosa of the wall of the bladder.
Eosinophilia in oncological pathologies is a frequent manifestation and is most often observed with tumor damage to the organs of the digestive tract and organs of the lymphatic system. Eosinophilic cells with this form of disease are found not only in the blood, but also in the tumor substrate. The presence or absence of eosinophilia in a patient with oncopathology does not have a significant effect on the prognosis of the underlying disease.
Eosinophilia of parasitic genesis is characterized by high rates of eosinophils in the blood, which is more than 3 × 109 / L. In connection with the similar clinical symptoms of this form of eosinophilia with eosinophilic syndrome, the patient needs to perform a number of microbiological studies for diagnostic purposes. In some cases, the localization of parasitic infestation is easy to determine even visually, since local inflammation forms in the lesion site, in the pathogenesis of which the cytotoxic function of eosinophils plays a large role. Thus, the clinical symptomatology of this form of eosinophilia is formed both by symptoms of direct helminthic invasion and by a common intoxication syndrome caused by the action of eosinophils.
Eosinophilia of the lungs is considered rare and the most difficult in the diagnostic plan pathology. This form of eosinophilia unites several pathologies that are significantly different in the clinical course of the disease, but have a single localization, that is, a predominant lesion of the pulmonary parenchyma. The most specific form of pulmonary eosinophilia is Leffler's syndrome, in which not only an increase in the number of eosinophilic cells in the circulating blood is observed, but also the appearance of eosinophilic infiltrative changes in the lungs that have a volatile character. This pathology is not accompanied by severe respiratory disorders and belongs to the category of random findings in the prophylactic ray examination of patients. Due to the fact that Leffler's syndrome does not have a significant effect on the health disorder, there is no specific treatment for this pathology, and only in the case of severe course short courses of corticosteroid therapy are used.
Eosinophilia in bronchial asthma is observed only in the case of a prolonged course of the disease and is characterized by the development of a typical chronic eosinophilic pneumonia. This pathology is more common among female patients and is accompanied by a progressive increase in the number of infiltrative and focal changes in the lungs, with concomitant moderate eosinophilia in the peripheral blood.
Eosinophilia in children
In childhood, eosinophilia is not uncommon, since in this period the person is most susceptible to allergic agents and parasitic infections. The peculiarity of eosinophilia in childhood is its stability and the absence of correlation between the severity of clinical symptoms and the degree of increase in the number of eosinophilic blood cells.
In 80% of episodes of eosinophilia in children with an additional examination of the child, signs of helminthic invasion caused by protozoa are found. The most persistent and high eosinophilia provokes toxocariasis during the migration of the causative larvae of the pathogen. This pathology differs not only in visceral manifestations in the form of hepatosplenomegaly, infiltrative changes in the lungs, but also in the damage to the skin, manifested by the appearance of a creeping rash with severe itching. At laboratory research besides the expressed degree of an eosinophilia it is possible to find out anemic syndrome and a hypoglobulinemia. The first visual signs of helminthic invasion in children is pronounced itching in the perineal region, local hyperemia of the perianal region and disturbance of night sleep.
A separate group of patients with signs of eosinophilia are children who suffer from hereditary diseases in the form of familial histiocytosis and severe congenital immunodeficiency syndrome. The presence in the child of signs of a violation of the intestinal digestive function should always suggest an eosinophilic form of gastroenteritis, since this pathology needs specific treatment and monitoring of the patient.
The transient type of eosinophilia can be considered as a variant of the norm in children born before the term, and these changes do not need a medical correction. The persistent progression of eosinophilia is indicative of pronounced anabolic disorders and needs careful follow-up of the child in order to identify the causes of its occurrence. Some intrauterine infections are accompanied by signs of eosinophilia, observed immediately after birth.
During the period of introduction of the first complementary foods, the majority of babies may have signs of atopic allergic reaction in the form of dermatitis, accompanied by transient eosinophilia disappearing together with cutaneous manifestations after removal of the allergic agent.
Treatment of eosinophilia
To determine the tactics of management and treatment of a patient with laboratory signs of eosinophilia, the patient should be thoroughly examined and the root cause of this blood pathology should be established. In most cases, the use of eosinophilia therapy of etiopathogenetic orientation has positive results and contributes to the speedy recovery of the patient.
The fundamentally important in the diagnosis of the causes of eosinophilia has a carefully collected history of the patient's life, including the definition of the main complaints of the patient, the conditions and the time of their occurrence. It is necessary to take into account the hereditary factor of occurrence of eosinophilia, since these pathology forms need specific correction and dynamic observation of the patient.
So, the diagnosed eosinophilia of allergic genesis does not need specific therapy and its treatment consists in eliminating the allergic agent. In a situation where it is not possible to establish an allergen, non-specific desensitizing therapy (Cetrin 1 capsule once a day) is performed before the normalization of the eosinophil count in the circulating blood.
Pulmonary forms of eosinophilia in most cases do not require the use of medical methods of treatment, but in severe disease with severe respiratory disorders, the use of corticosteroid hormones by a short course of no more than 6 days is recommended (Prednisolone in a daily dose of 15 mg every other day). In the presence of a pronounced bronchospastic component, the use of an inhalation method for the administration of beta-adrenomimetics (Theophylline) is recommended. This category of patients is not subject to hospitalization and needs regular follow-up with a control X-ray examination.
With the reliable establishment of eosinophilia caused by helminthic invasion, it is recommended the use of course antiparasitic therapy (a single dose of Megendozol at a therapeutic dose of 100 mg).
For the treatment of eosinophilic myositis and fasciitis, glucocorticoid hormones in high dosage are considered as drugs of choice (Prednisolone in a daily dose of 60 mg orally, followed by a prolonged use of a maintenance dosage of 5 mg for at least two years). In the absence of persistent positive results and elimination of signs of eosinophilia, it is advisable to prolong the appointment of cytostatic drugs (Azathioprine in a daily dosage of 150 mg).
With local local lesions of the skin and lymphatic reservoirs, methods of physiotherapy (phonophoresis with trinolone B, DMSO application) are widely used. In the case of a severe progressive course of eosinophilia, hemosorption has a good effect, but this method of treatment is used only if there is no visible result from the use of other therapies.
In the treatment of pediatric patients with signs of eosinophilia, expectant management is used, and only with the progressing course of the disease with rapidly increasing rates of eosinophilic cells in the blood test is the use of hormonal therapy.