What do eosinophils do and when do they become more numerous?
Eosinophils are formed in the bone marrow and most of the time are found in tissues: in the mucous membrane of the respiratory tract, intestines, and skin. There are few of them in the blood, so even a slight increase is noticeable in the analysis. These cells secrete active substances that destroy the membranes of parasites and at the same time participate in allergic inflammation. The number of eosinophils fluctuates throughout the day and increases with exacerbation of allergies. The doctor assesses the degree of increase: mild, moderate and severe eosinophilia require different amounts of examination.
- Mild eosinophilia - most often allergies and medications
- Moderate – parasitosis, drug reactions, skin diseases
- Severe - requires mandatory examination
- Tissue eosinophilia without changes in the blood
- Hypereosinophilic syndrome with organ damage
Reasons
In adults in countries with temperate climates, the first place is occupied by allergic diseases: hay fever, bronchial asthma, atopic dermatitis, allergic rhinitis, urticaria. The second is drug reactions: eosinophilia may be the only manifestation, but is sometimes accompanied by rash and fever. Parasitic causes are especially significant where helminthiases are common: ascariasis, toxocariasis, opisthorchiasis, strongyloidiasis, echinococcosis. Less commonly, the increase is associated with systemic connective tissue diseases, inflammatory bowel diseases, adrenal insufficiency and blood diseases.
- Bronchial asthma, hay fever, atopic dermatitis
- Drug allergies and reactions to drugs
- Helminthiases: ascariasis, toxocariasis, opisthorchiasis, strongyloidiasis
- Giardiasis and other protozoa
- Allergic bronchopulmonary aspergillosis
- Systemic vasculitis and connective tissue diseases
- Inflammatory bowel diseases
- Tumors and diseases of the bone marrow
How it manifests itself
Eosinophilia has no specific symptoms: the underlying disease determines the complaint. Allergies include itching, rash, sneezing, nasal congestion, and bouts of difficulty breathing. With helminthiasis - abdominal pain, unstable stool, itching, and sometimes cough during the migration of larvae. In case of a drug reaction, a rash, fever, and enlarged lymph nodes appear one to several weeks after starting to take the drug. With prolonged severe eosinophilia, organs suffer: shortness of breath, heart failure, swelling, numbness and weakness in the arms and legs.
- Itching, rash, urticaria
- Nasal congestion and sneezing
- Attacks of coughing and difficulty breathing
- Abdominal pain and unstable stool
- Temperature and enlarged lymph nodes during a drug reaction
- Shortness of breath and swelling due to organ damage
Survey
They begin with a repeated blood test and calculation of the absolute number of eosinophils, as well as with detailed questioning: when it started, what medications were taken, whether there were any trips, contact with animals and soil. Total IgE and allergy testing help confirm the allergic nature. To search for parasites, a single stool test is not enough - it is taken three times at intervals, supplemented by blood tests for antibodies to individual pathogens. With severe and persistent eosinophilia, the condition of the heart and lungs is assessed and referred to a hematologist.
- Complete blood count with absolute eosinophil count
- General IgE and allergy tests
- Feces for helminth eggs three times
- Feces for Giardia antigen
- Blood tests for antibodies to helminths
- Chest X-ray
- EchoCG and ECG with severe eosinophilia
- Consultation with a hematologist and bone marrow examination if indicated
Treatment
They treat the cause, not the number. In case of allergies, basic therapy is selected and contact with the allergen is eliminated; in case of confirmed helminthiasis, a course of antiparasitic drugs prescribed by a doctor taking into account the pathogen is administered. Preventive anthelmintic therapy without examination is not justified: the drugs do not act on all parasites and are unsafe. If eosinophilia appears after starting a new medication, the doctor decides whether to discontinue it. For hypereosinophilic syndrome, treatment is carried out by a hematologist, it is aimed at protecting organs from damage.
- Treatment of allergic disease
- Antiparasitic drugs based on examination results
- Discontinuation or replacement of the drug in case of a drug reaction
- Monitoring blood tests after treatment
- Hand hygiene, washing vegetables and fruits, processing meat and fish
- Observation by a hematologist for persistent severe eosinophilia