Basophils can be low due to conditions like pregnancy, ovulation, acute infections or hyperthyroidism. Low basophils can also occur with certain treatments, like corticosteroid medications, chemotherapy or radiation therapy.

Basophils are a type of white blood cells that are a part of the immune system. They fight infections caused by bacteria, viruses, fungi or parasites,. They also release histamine when in contact with allergenic substances or heparin, to prevent the formation of blood clots.

Basopenia, which is the medical term for low basophils, is detected through blood tests, and is characterized by a level that is less than 20 basophils per μl of blood. It can also be confirmed through a bone marrow biopsy, as this is where blood cells are produced.

What causes low basophils?

Basophils levels can be low due to:

1. Pregnancy

Low basophils can be caused by normal hormonal changes during pregnancy or postpartum. This finding is generally not a cause for concern, as they return to normal levels after these phases.

However, women should me monitored periodically to assess whether there are other causes for low basophils, such as infections or abnormal thyroid functioning.

What to do: during pregnancy, prenatal consultations should be maintained regularly and all tests ordered by the obstetrician should be completed. These tests should include a blood count to evaluate the blood cell count, and to determine whether there is a cause for low white blood cells.

2. Ovulation

Hormonal changes in the menstrual cycle, especially during ovulation, can also cause low basophils. This level recovers and returns to normal during the luteal phase.

Ovulation generally occurs between the 10th and 14th days after the first day of a period in women who do not use birth control. Ovulation can present with symptoms like clear vaginal discharge, increased body temperature or pain in the lower abdomen. Learn more about how to identify ovulation symptoms and when they most typically occur.

What to do: low basophils during ovulation is a normal condition that does not require medical treatment. However, woman that also have other period symptoms, weight loss, hand tremors or fever, for example, should consult their doctor. gynecologist or endocrinologist for further testing. These are signs that another health condition could be causing low basophils, such as hyperthyroidism or infections.

3. Hyperthyroidism

Hyperthyroidism is a disease associated with abnormal thyroid functioning. Specifically, the thyroid produces excessive amounts of thyroxine, leading to an increase in the body's metabolism.

This dysregulation of thyroid hormones, especially when hyperthyroidism is not well controlled, can affect the immune system and white blood cell production. It can lead to a low level of basophils and neutrophils.

What to do: You should consult an endocrinologist to carry out blood tests, such as a complete blood count and other thyroid tests. If confirmed, the doctor may initiate treatment, which may involve medications like propylthiouracil or methimazole, iodine therapy or even surgery.

4. Thyrotoxicosis

Low basophils can also arise due to thyrotoxicosis, which corresponds to high levels of thyroid hormones in the blood, such as T3 and T4. It may be related to taking excessive doses of thyroid medications, such as levothyroxine.

Other causes of thyrotoxicosis include Graves' disease, thyroiditis, toxic adenoma, pituitary gland tumor or toxic multinodular goiter.

What to do: treatment should be guided by an endocrinologist, and will vary depending on the underlying cause of thyrotoxicosis. The doctor may prescribe medications to relieve symptoms, such as propranolol, or medications to reduce thyroid levels, such as propylthiouracil or methimazole, as well as to iodine therapy.

5. Acute allergic reaction

An acute allergic reactions, such as allergies to food, medications or other substances can lead to low basophil levels. With a reaction, basophils travel to the skin and lymphoid tissues, releasing histamine and inflammatory cytokines and causing an allergic response.

The symptoms of an acute allergic reaction may include generalized itching, hives, red bumps on the skin, a feeling of a closed throat, swelling in the mouth, tongue or face.

What to do: you should seek medical attention immediately or proceed to the nearest emergency room, as an acute allergic reaction is a serious situation that can be life-threatening.

6. Spontaneous chronic urticaria

Chronic spontaneous urticaria is a disease characterized by the appearance of blisters or reddish plaques on the skin, as well as intense itching, a burning sensation and swelling of the skin. These symptoms can last more than 6 weeks and can be caused by immunological factors.

This disease leads to low basophils due to a migration of basophils from the blood vessels to the skin.

What to do: the treatment should be guided by a dermatologist, who may recommend high-dose antihistamines to relieve symptoms, or immunosuppressive drugs, such as cyclosporine. In some cases, monoclonal antibodies, such as omalizumab, can be beneficial when antihistamines are not effective.

7. Acute infections

Low basophils can also arise due to acute infections. Basophils are part of the immune system and help to fight infections. Therefore they can become reduced when they migrate to the site of infection.

What to do: the infection should be treated as determined by a family doctor or infectious disease specialist. Treatment will vary depending on the type of microorganism causing infection, and the doctor may prescribe antibiotics, antivirals, antifungals or antiparasitics as appropriate.

8. Chronic use of corticosteroids

The chronic use of high doses of oral corticosteroids can lead to a decrease in basophils, as the basophils will generally migrate to the site of any inflammation.

Corticosteroids are steroid anti-inflammatory drugs, which reduce the production of inflammatory substances in the body. They are generally indicated for chronic diseases such as rheumatoid arthritis, asthma, chronic obstructive pulmonary disease or lupus.

What to do: you should attend regular follow-up appointments for the doctor to evaluate your treatment, doses and side effects with corticosteroids, the doses and the appearance of side effects. These medications can alter your immune system and reduce the body's ability to fight infections, which is why chronic use should be closely monitored.

9. Cancer treatment

Cancer treatment with chemotherapy can lead to low basophils as well as low levels of other components in the blood, such as neutrophils and platelets. This type of treatment stops the multiplication of cancer cells, but also affects the production of cells in other parts of the body, especially the blood, which are constantly renewed.

Radiation therapy can also lead to a decrease in blood cells, as it can affect their production in the bone marrow.

What to do: cancer treatment should be guided by an oncologist, who will typically order blood work before each chemotherapy session, or on a regular basis for radiation therapy. Very low blood counts may be treated with filgrastim injections or even a blood transfusion if your platelets are very low.