Leukemias are cancers that involve certain cells of the body’s blood, bone marrow, or immune system. Lyme disease is a bacterial infection that people can catch from tick bites. Although these conditions are very different, certain connections may exist between them.

As a 2021 review explains, leukemias are cancers that develop from certain cells called leukocytes. When someone has leukemia, some of their leukocytes grow and divide in an uncontrolled fashion. Doctors can classify such cancers according to whether they affect myeloid or lymphoid cells. These cells are kinds of leukocytes.

As the review notes, there are many possible genetic and environmental causes of leukemia.

Lyme disease is the result of Borrelia burgdorferi bacteria. These bacteria can make their way into a person’s body via tick bites. Ticks are small arachnids that feed on blood, and that can carry B. burgdorferi bacteria.

This article will look into the possibility that Lyme disease is a risk factor of leukemia. It will also look into what it is like to have both conditions at the same time, and at whether Lyme disease could mask or be mistaken for leukemia.

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There is no strong connection between Lyme disease and leukemia. But some evidence shows that Lyme disease may increase a person’s risk for another type of blood cancer called lymphoma. This may be because of the inflammation that Lyme disease causes in the body.


There is some evidence that Lyme disease is a risk factor of lymphomas. But this risk is small, and the link is not clear.

Lymphomas are cancers that affect a person’s lymphoid cells. These cells are components of the immune system, and lymphomas are among the most common cancers affecting the immune system.

The American Cancer Society (ACS) notes that some people with a B. burgdorferi infection, which causes Lyme disease, developed skin lymphomas in Europe. But the ACS emphasizes that most individuals with Lyme disease will not develop skin lymphomas.

Learn about leukemia and lymphomas here.


Scientists believe that bacterial infections such as Lyme disease could increase a person’s cancer risk by causing inflammation in the body. Up to 25% of cancer causes may include infections and inflammation.

Although scientists are not certain about how this process works, one hypothesis is that inflammation damages DNA. This could lead to cancer-causing genetic mutations.

Learn more about the causes of leukemia here.

It is possible for someone to develop Lyme disease and leukemia at the same time. This person could then develop symptoms of both conditions. Symptoms of Lyme disease and leukemia can overlap and may be variable, meaning not all people experience the same symptoms.

Symptoms of leukemia

Leukemia symptoms can vary according to the type of leukemia a person has. Common symptoms of leukemia include:

Learn more about leukemia symptoms here.

Symptoms of Lyme disease

Common symptoms of Lyme disease include:

Learn more about the symptoms of Lyme disease here.

Lyme disease progresses through different stages.

There is evidence that people who have both leukemia and the “bull’s-eye” rash are more likely to have a more developed form of Lyme disease than those with the rash alone.

Treating Lyme disease and leukemia

Antibiotics are the typical treatment option for Lyme disease. A doctor may prescribe an antibiotic called doxycycline for around 10–14 days.

Scientists believe that this treatment is equally effective for people with and without leukemia. It does not raise the risk of complications in people with leukemia.

Since the typical symptoms of leukemia and Lyme disease are different, it is unlikely that Lyme disease could mask leukemia.

Some people with leukemia develop a rash on their skin. This happens because of blood vessels that burst under the skin. A person with a leukemia rash may be concerned that the rash is a sign they have Lyme disease. But the rash that can sometimes happen with Lyme disease can be a distinctive “bull’s-eye” rash. A rash is present in around 70–80% of people with Lyme disease.

See pictures of leukemia rashes here.

See a picture of a Lyme disease rash here.

Because Lyme disease and leukemia have different symptoms and work in very different ways, it is also unlikely that healthcare professionals would mistake Lyme disease for leukemia.

A person who is concerned about any rash they have developed should contact their doctor.

If a person is concerned that they have developed Lyme disease, they should speak with their doctor. As the Centers for Disease Control and Prevention (CDC) explains, doctors must consider several factors when making a diagnosis of Lyme disease. These include:

  • relevant signs or symptoms
  • the likelihood that someone came into contact with a B. burgdorferi-carrying tick
  • the possibility of a different disease with similar symptoms
  • results of laboratory testing

Treatment for Lyme disease can start even without a confirmed diagnosis.

Individuals with both Lyme disease and leukemia may also wish to discuss the healthcare implications of having both conditions.

The treatment for Lyme disease usually involves antibiotics, which are typically safe for a person with leukemia to take.

The CDC contains some useful information about how to help prevent tick bites.

For example, although ticks are present all year round, they are at their most active during warmer months. In the United States, this means they are most active between April and September.

Ticks also prefer grassy or wooded areas. By limiting exposure to these environments at those times, a person can lower their chances of getting a tick bite.

People can also treat any outdoor gear or clothing with products that contain 0.5% permethrin, and by using EPA-registered insect repellents. Regularly checking clothing and exposed body parts while outdoors can help locate ticks before they bite.

Covering the body with long-sleeved or long-legged clothing can also protect the skin from tick bites.

Learn more about Lyme disease prevention here.

There is some evidence that inflammation due to Lyme disease can sometimes cause certain forms of blood cancer, such as lymphoma. But most people with Lyme disease do not develop leukemia.

Some people with leukemia develop a rash due to burst blood vessels. But it is usually distinguishable from the “bull’s-eye” rash that Lyme disease can cause.

Treatment for Lyme disease involves antibiotics, which are safe for people with leukemia to take.

People can easily take steps to reduce their chances of catching Lyme disease, including wearing long-sleeved clothing or long-legged trousers when in areas with long grass.