Poikilocytosis – Causes, Symptoms, Diagnosis, Treatment

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People having abnormally shaped red blood cells (RBCs) in their blood suffer from a condition called Poikilocytosis. Poikilocytosis is an umbrella expression that describes an assortment of oddly shaped cells and, therefore, takes its name from the Greek word ‘Poikilos’ meaning varied, diverse or wide-ranging.

Red blood cells, the most common type of blood cells, that are also known as red blood corpuscles or RBCs, are the primary carriers of oxygen in a vertebrate. They carry oxygen through the bloodstream in the circulatory system. These RBCs absorb the oxygen in the lungs and discharge it into the body tissues while passing through the capillaries.

However, when these RCBs are abnormally shaped, their task of carrying oxygen to various parts of the body is often hampered. They not only carry oxygen, but also deliver nutrients throughout the body. Thus, it can affect your overall health condition. This disorder, though a life-threatening one, is also easily treatable. The first step is to identify the specific cause of the disorder to get the appropriate treatment.

What is Poikilocytosis?

The blood plasma contains both White Blood Cells or WBC and Red Blood Cells or RBC.  When the malformed RBCs are found to be in excess of ten percent of the total blood content, the condition is referred to as Poikilocytes which can, of course, be very harmful to the individual.

This problem is quite frequently found in wild as well as domesticated animals. most particularly those that chew cud like cows, goats, and deer. It is also found in humans, but to a lesser degree.

Red Blood Cells are flat and rounded in shape like a disk, but individuals with poikilocytes can carry RBCs that are either elongated or flatter than usual. Sometimes they are in the shape of a teardrop with sharp protrusions.

The main job of a red blood cell is to carry nutrients and oxygen to all the organs and tissues of the body, but due to their peculiar shapes, it becomes a hindrance for them to carry enough oxygen which can ultimately lead to critical health problems. Poikilocytosis can lead to serious problems like cardiovascular ailment, lack of nutrient supply to the blood and breathing problems and can even be fatal in some cases.

Types of Poikilocytosis

Poikilocytosis can be classified into different types based on the shape that the cells assume. There is quite a lot of diversity in the cell shapes and as such, Poikilocytosis can be classified into the following types:

1. Stomatocytes:

They are oval shaped and usually resemble wrinkled lips due to their three-dimensional structure that is capped with an end.

Cause of condition: Hereditary stomatocytosis, alcoholism, Rh null phenotype and hepatic disorders as well as liver disease.

They usually occur in marine creatures and woodchucks.  However, in the case of dogs, they lead to dwarfism, especially in the Alaskan Malamutes species.

2. Drepanocytes:

They are also known as sickle cells as they are in the shape of a crescent with spikes.

Cause of condition: Sickle cell anemia

Mostly found in sheep and deer, but could be present in humans due to hereditary hemoglobin defect. The malformed ‘S’ shaped hemoglobin could be due to the combination of hydrophobic valine and hydrophilic glutamic acid in the blood.

3. Ovalocytes:

These RBCs are somewhat oval in shape. There are three types of Elliptocytes and all three depend on the length of the abnormal cell.

Cause of Condition: Anemia, hereditary elliptocytosis, and thalassemia

Mostly found in dogs and cats.

4. Spherocytes:

These are solid, rounded, small cells.

Cause of Condition: Severe burns, transfused cells, genetic spherocytosis, new-born jaundice, immune-mediated hemolytic anemia, and genetic spherocytosis.

Mostly found in horses, cats, and cattle.  However, in the rare case of dogs, the center portion is typically pale.

5. Dacryocytes:

These cells have a bulging head with a pointed end almost like a teardrop.

Cause of condition: Beta thalassemia major, myelophthisic anemia, myelofibrosis with myeloid metaplasia, extramedullary hematopoiesis, and leukemia.

6. Leptocytes:

These are flat, thin cells with hemoglobin present at the edge of the cell.

Cause of condition: Most commonly occur in patients with thalassemia.

7. Codocytes:

They resemble a bull’s eye and hence, referred to as target cells.

Cause of condition:  Hemoglobin C disorder, Cholestatic liver disease, and thalassemia are the main reasons for this type of Poikilocytosis.

8. Echinocytes:

Also referred to as Burr cells. Their outer casing has blunt, evenly spaced protrusions on the edges.

Cause of condition: Microangiopathic hemolytic anemia, severe stomach diseases like cancer or ulceration, uremia, neonates, and pyruvate kinase deficiency, and kidney diseases.

Generally occurs in horses and kidney of dogs.  Coral snake, rattlesnake, and viper venom consists of echinocytes. Therefore, snake poison can be a primary cause for the increase of burr cells.  Echinocytes can form and reproduce in the plasma immediately within twenty-four hours of a snake bite.

9. Schizocytes:

They are disjointed or split RBCs having no particular shape.

Cause of condition: Disorders in platelets such as coagulation disorder, purpura, microangiopathic hemolytic thrombocytosis, severe burns and hemolytic uremic syndrome and anemia. In this case, the smooth endothelial lining becomes rough causing turbulence in the blood flow. They are also responsible for the fragmentation of red blood cells.

Usually, occurs in cats and dogs though quite rare in cats.

10. Acanthocyte:

Also known as spur cells for their thorny projections and an irregular arrangement. They generally have a short lifespan due to their stiff

Cause of condition: Anemia, severe liver disorder, microangiopathic hemolytic, vitamin E deficiency and abetalipoproteinemia, neuroacanthocytosis.

They are mostly observed in horses, cats, cattle, and dogs.

11. Keratocytes:

These cells are shaped like a helmet.

Cause of the condition: Could happen due to blisters. The presence of keratocytes can indicate oxidant injury, fragmentation injury, or liver disease.

Mostly found in dogs and cats, sometimes even in healthy cats.

12. Degmacytes:

They have a nibbled appearance and hence, the name Bite Cells.

Cause of condition:  Liver cirrhosis G6PD, hemolytic anemia, and poisoning.

13. Phantom cells/Semilunar bodies/Ghost cells

The cells are in the shape of a crescent and discolored due to lack of hemoglobin.

Different Causes of Poikilocytosis

Lack of vitamin B12 and folic acid are the causes of Poikilocytosis. When the intestine is deprived of vitamin B12 in sufficient quantities, it leads to poor absorption of nutrients and folic acid resulting in Poikilocytosis. Vital nutrients are essential for the proper functioning of the body. But when vitamins such as vitamin B12 are absent, it causes the RBCs to form prematurely that can then probably injure the host, leading to anomalies in the shape of red blood cells.

However, scarcity of folic acid and iron in the bloodstream could also be brought about by medical circumstances like regional enteritis, celiac disease, and tropical sprue. Cancer could also be another reason for Poikilocytosis. This disease can be inherited as well as acquired.

Inherited Causes:

  1. McLeod syndrome which affects your heart, nerves, and blood.
  2. Spherocytosis and elliptocytosis could also be responsible for this disease.
  3. Thalassemia where the body is likely to produce oddly shaped hemoglobin
  4. Sickle cell anemia which is usually a genetic cause for deformed RBCs that are crescent-shaped.

Acquired Causes:

  1. Anemia which is due to iron deficiency in the body.
  2. Megaloblastic anemia which is caused due to a deficiency in vitamin B-12.
  3. Autoimmune hemolytic anemia where the immune system begins to destroy the red blood cells.
  4. Lead poisoning, alcoholism, and chemotherapy are also some of the causes of Poikilocytosis.

Symptoms of Poikilocytosis

  • Severe growth impediment
  • Cardiovascular problems
  • Deficiency in the supply of oxygen to organs
  • Weight loss
  • Nutrient deficiency
  • Irregular breathing

Diagnosis of Poikilocytosis

The following tests are undertaken to diagnose Poikilocytosis –

  1. The primary test is blood film test to identify abnormal RBCs and also help identify the category of Poikilocytosis. Blood from the individual is extracted and examined under a high-resolution microscope.
  2. Blood count test is conducted to find out the degree of difference in the number of abnormal RBCs in your blood.
  3. A hemoglobin test and blood composition test are further done to confirm the hemoglobin count and amount of enzymes in the bloodstream respectively.
  4. Other tests including bone marrow testing are also carried out.

Treating Poikilocytosis

Some of the foods and supplements that are helpful for patients suffering from this disease are given below:

  • Since Poikilocytosis is generally due to a shortage of folic acid and vitamin B12, patients are given supplements rich in nutrients to bring their blood plasma content back to normal.
  • Folic acid helps in the development and growth of red blood cells. So, when there is a lack of iron and folic acid, the RBCs become under-developed and their growth is hampered. Therefore, it is essential to consume food rich in iron which helps in increasing the RBC count.
  • Foods that are a good source of proteins such as almonds, soy products, egg yolk, meat, whole grains, and lentils, help in pacifying the functioning of the intestinal system and boosting the nutrient content in the body. It is imperative that the intestine stays in a healthy condition as it is responsible for absorbing the nutrients from the foods.
  • Consumption of legumes is also advised, along with leafy vegetables like broccoli, cabbage, and spinach as well as beet that are rich in iron and filled with nutrients.
  • However, in rare cases where the celiac disease has been detected, patients are advised to take a gluten-free diet including soy, wheat and certain vegetables and fruits.
  • In case the doctor confirms the patient to be suffering from blood cancer due to excess of poikilocytosis, the patient might have to undergo chemotherapy.

Poikilocytosis Prognosis

The lasting prognosis for poikilocytosis is entirely based upon the reason for the illness and the prompt treatment you receive. Anemia due to a deficiency in iron is curable, but it can be risky if not treated in time. Pregnant women are at great risk if they happen to suffer from anemia as it can lead to complications during pregnancy like neural tube defects.

Anemia due to a genetic disorder (sickle cell anemia) will perhaps need lifelong treatment.  However, the latest medical developments promise assured treatments for certain genetic blood disorders.

There has to be a change in lifestyle where the regular consumption of recommended vitamin-rich foods and supplements will make the RBCs in the plasma return to a healthy condition.  You need to closely follow the doctor’s advice to see a quick recovery. And this healthy lifestyle should be maintained post recovery.

Diagnosis of Poikilocytosis

The following tests are undertaken to diagnose Poikilocytosis –

  1. The primary test is blood film test to identify abnormal RBCs and also help identify the category of Poikilocytosis. Blood from the individual is extracted and examined under a high-resolution microscope.
  2. Blood count test is conducted to find out the degree of difference in the number of abnormal RBCs in your blood.
  3. A hemoglobin test and blood composition test are further done to confirm the hemoglobin count and amount of enzymes in the bloodstream respectively.
  4. Other tests including bone marrow testing are also carried out.

Poikilocytosis vs Anisocytosis


Aniso is the root word for Anisocytosis which simply means unequal. Hence, an excess of RBCs having an uncharacteristic and unusual size in the blood plasma is known as Anisocytosis.

Anisocytosis is an uncommon medical condition characterized by the presence of RBCs that are not equal in size. This disease commonly occurs in people who suffer from thalassemia, anemia, or any type of blood disorder. It is primarily caused due to iron deficiency in the blood cells that lead to a reduction in the size of the blood cells.

The major difference between Poikilocytosis and Anisocytosis is that RBCs in the former are abnormal in shape while the RBCs in the latter are of an unusual size.

Symptoms of Anisocytosis

  • Irregular heartbeat
  • Breathlessness
  • Pallid skin
  • Extreme exhaustion
  • Dizziness
  • Tiredness
  • Chest pain
  • Headache
  • Cold feet

Causes of Anisocytosis

  • Deficiency of iron
  • Myelodysplastic Syndrome
  • Deficit of vitamin A
  • Diamond-Blackfan anemia
  • Lack of care post blood transfusion
  • Deficit of vitamin B12

Tests & Diagnosis

Thyroid gland function, anemia, calcium deficiency, and adrenal gland function tests are some of the tests carried out to identify this disease.

Blood smear tests are done under a microscope to analyze their composition. Many aspects like cell volume, the width of red cells, the number of red cells, and the average amount of hemoglobin in each RCB are considered. In this way, the type of Anisocytosis is established.

Types of Anisocytosis

Anisocytosis is usually classified into the following types –

  • Microcytosis – The RBCs are smaller in size than normal.
  • Normocytic anemia – The RBCs are normal in size, but the cell count is low.
  • Macrocytosis – The RBCs are larger in size than usual.


Anemia being the chief reason for Anisocytosis, the best approach of treatment would be to consume foods rich in iron viz. fish, pulse, brown rice, meat, eggs, and beans. However, additional supplements can also be taken to treat this condition.


Red blood cells are intended to be of a particular size and shape, but when a person possesses irregularly shaped red blood cell (RBC) in their bloodstream, they are said to be suffering from a condition called Poikilocytosis. These oddly shaped red blood cells can create medical issues for the body as they can get trapped leading to clots. Though this malady is not so common in humans, if contracted, it can lead to insufficient oxygen circulation in the body.


There are various causes for this disease, the main one being a vitamin deficiency, precisely of Vitamin B12.  Additionally, lack of folic acid can also be a cause for the change in shape of red blood cells, thereby making them less competent to carry out their specific job in the human body.

Vegetarians are at risk as vitamin B12 is obtained from animal products and as explained earlier, lack of this vitamin is one of the major causes for Poikilocytosis.  Therefore, a reasonable amount of vitamin B12 is essential to prevent this illness.


As these malformed red blood cells are a hindrance for the proper circulation of oxygen in the body, patients with poikilocytosis experience symptoms like breathlessness and lethargy as their body strains to get the oxygen it requires. And due to this unwanted struggle and strain, the heartbeat is quickened.  Further, insufficient supply of oxygen to the brain leads to fatigue and reduction in concentration levels.

Due to the insufficiency of oxygen, the skin sometimes becomes sallow and the body, in general, gradually begins to break down due to the deformed red blood cells.


If the cause of poikilocytosis is due to improper diet, it is not something too difficult to rectify as the necessary changes can easily be made to get more of the particular vitamin which is lacking, in this case, vitamin B12.  Apart from dairy products, eggs and meat, vegetables rich in iron like beans, parsley, asparagus, leeks to name a few, would also be a good choice. You will have to maintain this diet for a few weeks or months to observe whether the symptoms are reduced.

In the case of cancerous poikilocytosis, chemo treatment may be recommended to eradicate the abnormal cells.

Diagnosis of Poikilocytosis

Poikilocytosis can be detected by a blood smear test. This test is done by spreading a thin layer of blood on a microscopic slide to help separate the cells and distinguish between the shapes and sizes of the Red Blood Cells.

It’s not that every single red blood cell is deformed. People with poikilocytosis have mixed cells i.e. normally shaped cells as well as abnormally shaped cells. The only difference being the latter is in excess and the very cause for the disease.

Most often there are quite a few distinctive types of poikilocytes present in the blood and the only person who can be able to identify which shape is most widespread is your doctor.

Your doctor will most probably conduct more tests to locate the cause of your RBCs becoming abnormal in shape.  Make sure to be very transparent with your doctor about your medical history and your symptoms and/or if you are on any kind of medication.

Examples of other diagnostic tests include:

  • Serum iron levels
  • Liver function tests
  • Bone marrow biopsy
  • Ferritin test
  • Pyruvate kinase test
  • Complete blood count (CBC)
  • Folate test
  • Vitamin B-12 test


Patients diagnosed with poikilocytosis are required to follow their physician’s instructions diligently.  An early recovery is possible only when a proper, healthy routine is maintained. It would be wise to have regular tests done to avert the development of variant cells at the onset and also to make certain the body is not missing the requisite nutrients. Despite the above, if the symptoms persist do visit your doctor immediately without wasting time.

You cannot expect this blood condition to be cured without being practical and positive by adopting the necessary changes to your normal lifestyle. So, the best decision you can make would be to start including more iron and vitamin B12 in your diet.  Iron is the chief constituent of hemoglobin and that is the reason you must get more iron into your daily diet.

People with this condition can definitely lead a normal life provided the symptoms are taken care of immediately. But, if you choose to disregard the problem it may lead to some other diseases and medical issues.

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