The Eosinophilia Is the increase in eosinophils - a type of white blood cells - that are being recruited to a specific site in the body. Eosinophilia is spoken when values indicate more than 500 eosinophils per m³.
An eosinophil count is a type of blood test that measures the amount of eosinophils in the body, and typically helps the doctor to confirm a diagnosis.
White blood cells are an important part of the body's immune system, and are vital to protect it from invasive bacteria or parasites. Each white blood cell lives from several hours to 12 days and then a new white blood cell replaces it, although the half-life is five days.
High levels of white blood cells in the blood are an indicator of the presence of a disease or infection, since they mean that the body is sending more and more white blood cells to fight infection.
Eosinophils are a type of white blood cell that develops in the bone marrow, and they have two distinct functions in the immune system: they destroy invading germs like viruses, bacteria, or parasites like Giardia and Pinworm, as well as They create an inflammatory response, especially if it is an allergy.
Inflammation is neither good nor bad. It helps to isolate and control the immune response at the site of an infection, but also damages the tissue around it. Allergies are immune responses that often involve chronic inflammation. Eosinophils play an important role in inflammation related to allergies and asthma.
Causes
Eosinophils play two roles in their immune system:
Destroy foreign substances: for example, they fight substances related to a parasitic infection that have been marked for destruction by the immune system.
Regulate inflammation: Eosinophils help promote inflammation, which plays a beneficial role in the isolation and control at the site of the disease.
But sometimes the swelling may be greater than is necessary, which can lead to annoying symptoms or even tissue damage.
Eosinophils play a key role in asthma symptoms, allergies, as well as hayfever. Other disorders of the immune system may also contribute to ongoing (chronic) inflammation.
Eosinophilia can be caused by a variety of factors, including:
- Parasite and fungal diseases
- Allergies including allergies to medicines or foods
- Adrenal conditions
- Skin Disorders
- Toxins
- Autoimmune diseases
- Endocrine Disorders
- Tumors
Specific diseases and conditions that can result in blood or tissue eosinophilia include:
- Acute myelogenous leukemia (AML)
- Ascariasis (an infection of worms)
- Asthma
- Atopic dermatitis (eczema)
- Cancer
- Churg-strauss syndrome
- Cholecystitis (inflammation of the gallbladder)
- Allergy to a drug
- Eosinophilic esophagitis
- Eosinophilic Leukemia
- Hay fever
- Hodgkin's lymphoma
- Hypereosinophilic Syndrome
- Idiopathic hypereosinophilic syndrome (HES), an extremely high eosinophil count of unknown origin
- Lymphatic filariasis (a parasitic infection)
- Ovarian cancer
- Parasitic infections
- Primary Immunodeficiency
- Trichinosis (an infection of the rounded worm)
- Ulcerative colitis
Parasitic diseases and allergic reactions to medication are among the most common causes of eosinophilia. Hypereosinophilia causing organic damage is called hypereosinophilic syndrome.
This syndrome tends to have an unknown cause or be the results of certain types of cancer, such as bone marrow or lymph node cancer.
symptom
Certain symptoms and physical findings may suggest associated causes or disorders, depending on their cause.
Examples include: fever, weight loss, myalgias, arthralgias, inflammation of the lymph nodes or glands, rashes (allergic, dermatological or vascular disorders), abnormal lung findings (asthma, lung infections, among others).
Additional tests for diagnosis
Additional tests often include:
A feces and parasite test. However, negative results do not rule out a parasitic cause, for example, trichinosis requires a muscle biopsy, visceral larva migrans and filarial infections require biopsies of other tissues, duodenal aspirates may be necessary to exclude specific parasites such as Strongyloides sp.
Other specific diagnostic tests are determined by clinical findings (particularly travel histories) and may include chest X-rays, urinalysis, liver and kidney function tests, and serological tests for parasite and connective tissue disorders.
If patients have generalized lymphadenopathy, splenomegaly or systemic symptoms, a blood test is performed.
An elevated serum vitamin B12 or anomalies in the peripheral blood smear suggest an underlying myeloproliferative disorder, and a bone marrow aspirate and biopsy with cytogenetic studies may be useful.
In addition, if the routine evaluation does not reveal a cause, tests are performed to detect organ damage. Tests may include some of the above, as well as LDH and liver function tests (suggesting liver damage or possibly a myeloproliferative disorder), echocardiography, and lung function tests.
Once a specific cause has been determined, additional testing may be necessary.
Treatment
Treatment for the many individual causes of eosinophilia, including associated parasitic and malignant forms, is beyond the scope of this article. However, there are some general guidelines:
Most cases of secondary eosinophilia are treated on the basis of their underlying causes. Allergic and connective tissue disorders may be amenable to treatment with corticosteroids. Parasitic and fungal infections can become worse or spread through the use of steroids and should be ruled out if indicated in the patient's history.
In patients with primary eosinophilia without involvement of the organs, no treatment is necessary.
Cardiac function should be evaluated at regular intervals. The responsiveness of steroids, both for prognosis (patients who respond to steroids improves) and to guide treatment when necessary, should also be assessed.
Options for the systemic treatment of primary eosinophilia with organ involvement initially include corticosteroids and interferon.
Other agents for steroid - resistant disease, which are often given as long - term maintenance regimens to control organ involvement, include: hydroxyurea, chlorambucil, vincristine, cytarabine, 2 - Chlorodeoxyadenosine (2 - CdA), etoposide and cyclosporine.
Patients with hypereosinophilic syndrome (HES) with unknown or negative PDGFRA have a low response rate to the medically imatinib.
However, treatment with antibodies and antibody-based agents (eg, mepolizumab, alemtuzumab, brentuximab vedotin) directed against targets expressed on the surface of eosinophils has been shown to be effective in some patients with HES.
In refractory cases, many combinations of chemotherapeutic agents, tyrosine kinase inhibitors (eg, imatinib) and monoclonal antibodies are being studied.
Non-myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) can also be considered in drug-refractory cases.
Frequent questions
Frequently asked questions about patients with suspected eosinophilia:
Why do I need an eosinophil count?
A physician may recommend an eosinophil count if he previously had a white blood cell count and the current results have changed abnormally.
A differential count test determines the percentage of each type of white blood cell present in the blood. This test will show you if you have an abnormally high or low count and if you have abnormal cells that occur with various diseases.
The doctor can also order this test if you want to confirm the diagnosis of certain diseases or conditions, such as:
- An extreme allergic reaction
- The initial stages of Cushing's disease, which is a disorder caused by the excess steroid hormone cortisol
- A parasitic infection
How do I prepare for an eosinophil count?
There are no special preparations needed for this test. Call your health care provider if you are taking any blood-thinning medicine such as warfarin (Coumadin), and give the general list of all medications and supplements you are taking.
Medications that can cause an increased eosinophil count include:
- - Appetite suppressants
- - Interferon, which is a drug that helps treat the infection
- - Some antibiotics
- - Laxatives containing psyllium
- - Tranquilizers
Your doctor may advise you to stop taking certain medications.
What do the results mean?
Normal results: A normal blood sample will show less than 350 eosinophil cells per microliter of blood.
Abnormal results: If you have more than 350 eosinophil cells per microliter of blood, then you have a condition known as eosinophilia. This may be due to:
- Allergic reaction to parasitic worms
- Autoimmune disease
- Eczema
- Asthma
- Seasonal Allergies
- Leukemia
- Ulcerative colitis
- Scarlet fever
- Lupus
- Crohn's disease
An abnormally low eosinophil count may be the result of alcohol intoxication or excessive production of cortisol, which is a naturally produced steroid in the body.
What are the complications associated with an eosinophil count?
An eosinophil count uses a standard blood drain, which is likely to have had many times in your life. As with any blood test, there is a minimal risk of minor bruising at the needle site.
In rare cases, the vein may swell after drawing blood. This is called phlebitis. You can treat this condition by applying a warm compress several times a day. If this is not effective, you should consult your doctor.
Excessive bleeding could be a problem if you have a bleeding disorder or if you take blood thinning drugs such as warfarin (Coumadin) or aspirin. This requires immediate medical attention.
What happens after an eosinophil count?
If the patient has an allergy or parasitic infection, your doctor will prescribe a short-term treatment to relieve symptoms and reverse your white blood cell count to normal.
If your eosinophil count indicates an autoimmune disease, your doctor may want to do more tests to determine what type of disease you have. They can then prescribe corticosteroids.
What are the warning signs that you may need an eosinophil count?
Any sign of severe allergies may indicate that you need to have your eosinophil count checked.
These signs include: sneezing and a stuffy nose, itching or congestion (nasal rhinitis); Burning or itching and red eyes (conjunctivitis); Difficulty breathing wheezing or persistent cough (asthma or bronchospasm); A red rash with itching and rash on the skin (urticaria or hives); Or a swelling of the soft tissues, especially in the lips, tongue or facial areas.
Simple pulmonary eosinophilia
Simple pulmonary eosinophilia is the swelling (inflammation) of the lungs due to an increase in eosinophils.
Causes
The majority of cases of simple pulmonary eosinophilia are due to an allergic reaction from:
A drug, such as a sulfonamide antibiotic or non-steroidal anti-inflammatory drug (NSAID)
Infection with a fungus such as Aspergillus fumigatus or jirovecii Pneumocystis.
A parasite, including lumbricoides Ascaridiasis, Necator americanus, or Ancylostoma duodenale (hookworms).
symptom
Symptoms can range from none to severe.
- Chest pain
- Dry cough
- Fever
- General ill feeling
- Rapid respiratory rate
- Eruption
- Difficulty breathing
- Wheezing
Tests and exams
The doctor will listen to the chest with a stethoscope. Crunchy sounds, called rales, can be heard. Estertores suggest an inflammation of the lung tissue.
A complete blood count (CBC) may show increased white blood cells, especially eosinophils.
Chest X-rays usually show abnormal shadows, called infiltrates. These may disappear over time or reappear in different areas of the lung.
A bronchoscopy with lavage may show a large number of eosinophils, and gastric lavage may show signs of the ascaris worm or other parasite.
Treatment
If you are allergic to a medication, your doctor may ask you to stop taking it. (Never stop taking a medication without first talking to the doctor).
If the condition is caused by an infection, it can be treated with an antibiotic or antiparasitic medication.
Corticosteroids (potent anti-inflammatory drugs) may sometimes be needed.
References
- Cottin V, Cordier JF (2010). "Eosinophilic lung diseases. Murray and Nadel's Textbook of Respiratory Medicine". Retrieved from: nytimes.com.
- Michaelann Liss, DO. (2016). "Eosinophilia Treatment & Management. Medscape". Retrieved from: medscape.com.
- Gotlib J. (2005). "Molecular classification and pathogenesis of eosinophilic disorders. Acta Haematol". Retrieved from medscape.com.
- Jussi J Saukkonen (2015). "Pulmonary Eosinophilia Treatment & Management. EMedicine". Retrieved from medscape.com.
- Corinna Underwood (2016)"Healthline Media". Retrieved from healthline.com.
- Mayo Clinic (2016). "Symptoms Eosinophilia. Newsletter: Mayo Clinic Health Letter". Retrieved from mayoclinic.org.
- Jane Liesveld (2016). "Eosinophilia. Merck Manual". Retrieved from merckmanuals.com.