What Is a Leukemia Rash? Pictures, Types, and More

Although rare, a leukemia rash can appear as tiny red dots on light skin or dark spots on dark skin.

A rash may indicate leukemia, a type of blood cancer, in rare cases. A leukemia rash can look like tiny dots, big plaques, or itchy bumps that don't turn white when pressed. Leukemia can cause this variety of rashes because of the cancer itself or from cancer treatments.

A healthcare provider cannot diagnose a leukemia rash by appearance alone; medical history and certain tests may be necessary to help with diagnosis. The rashes can be treated based on their cause and can include skin protection or medicinal options.

What Is a Leukemia Rash?

Leukemia is a type of blood cancer that changes how bone marrow functions. Bone marrow is where the body makes different cells, such as:

  • White blood cells, which fend off bacteria, viruses, and other threats
  • Red blood cells, which take oxygen from your lungs to your organs and tissues
  • Platelets, which slow down and stop bleeding through clots

With leukemia, genetic mutations cause bone marrow to make too many of one blood cell type, usually white blood cells. Those excess cells do not work correctly. The abnormal cells crowd out healthy cells, which causes symptoms like bruising, unintentional weight loss, and skin rashes.

Types of Leukemia Rash

Leukemia causes many types of rashes, such as:

  • Blastic plasmacytoid dendritic cell neoplasm (BPDCN): This type of leukemia typically presents as skin lesions similar to bruises. BPDCN might look like raised pimples or swellings, ranging from a few millimeters to several centimeters.
  • Infections: Both leukemia and its treatments can weaken the immune system. A weak immune system can cause frequent skin infections that cause swelling, pain, redness, pus, and itching.
  • Leukemia cutis: This condition develops when white blood cells leave the blood or bone marrow and infiltrate the skin. Leukemia cutis causes plaques, ulcers, blisters, or discolored lesions. Most people diagnosed with leukemia cutis are already diagnosed with leukemia.
  • Petechiae: Leukemia may cause problems with normal blood clotting, causing bleeding below the skin. Petechiae are little red dots that appear on light skin when tiny blood vessels, called capillaries, bleed under the skin. Petechiae can appear as dark red dots on dark skin.
  • Sweet syndrome: Leukemia—and granulocyte-colony stimulating factor drug, a leukemia treatment—may cause a sudden high fever and a rash of tender lesions, known as sweet syndrome.
  • Treatment rashes: Leukemia treatments—including chemotherapy, targeted therapy, and immunotherapy—may cause rashes. Rashes can appear on multiple body parts (e.g., scalp, neck, upper body). Symptoms include itching, burning, stinging, or pain.

Leukemia Rash Symptoms

Leukemia rash symptoms depend on what causes the rash. Generally, leukemia rashes cause symptoms such as:

  • Bruises
  • Easy bleeding
  • Itchiness
  • Pain
  • Pus, or a red streak around the rash
  • Raised patches of skin
  • Skin discoloration
  • Skin flakiness
  • Skin that's hot to the touch
  • Swelling

Pictures of Leukemia Rashes

Sometimes it can be difficult to tell if the rash you have is related to leukemia. The following are a few images of some types of rashes that can be associated with this blood cancer.

Leukemia cutis is rare but indicates a later leukemia stage. It can present commonly as firm or rubbery nodules or plaques.

Leukemia cutis

DermNet

Early leukemia rash can take the form of petechiae, which are 1 to 2 millimeters (mm) wide. The rash may keep its color instead of turning white.

Picture of petechiae
Petechiae.

Sweet syndrome may appear as a reddish-blue rash on light skin or black or brown on dark skin. The rash can contain tender plaques or nodules.

This photo contains medical imagery.

Someone with a Sweet's Syndrome rash on their back and neck
Sweet syndrome.

Reproduced with permission from © DermNet New Zealand www.dermnetnz.org 2023.

What Causes Leukemia Rashes?

With leukemia, the abnormal cells that grow out of control can migrate to other body parts, like the skin. Cancer cells can cause rashes when they spread.

Leukemia and its treatments can weaken the immune system, making it hard for the body to fight harmful bacteria, viruses, and fungi. Skin infections commonly occur among people with leukemia and cause rashes. Treatments can cause adverse reactions, including rashes, as well.

How Leukemia Rash is Diagnosed

Consult a healthcare provider if you have symptoms of a leukemia rash. A healthcare provider can perform a physical exam and discuss your personal and family history. They can refer you to a specialist if they cannot diagnose the source of your rash.

A healthcare provider will likely refer you for some tests if you have a rash and other symptoms of leukemia or another blood cancer. Tests commonly include blood tests and imaging.

Treatments for Leukemia Rash

Treatment for a leukemia rash depends on the cause. For example, a healthcare provider may advise the following if a leukemia rash results from treatments:

  • Applying mild soaps, lotions, or moisturizers
  • Changing your treatments or medications
  • Taking oral or topical medications
  • Using extra skin protection (e.g., wearing sunscreen and loose-fitting clothing)

A healthcare provider will likely directly treat the cause if a leukemia rash results from cancer cells spreading to the skin. Treatments may include chemotherapy, immunotherapy, radiation therapy, or a combination of methods.

How To Prevent Leukemia Rash

There is no one way to prevent leukemia rashes. Many causes of leukemia rashes are unpredictable reactions to the cancer or its treatments. Still, you might be able to help prevent some rashes if you:

  • Apply topical medications as prescribed.
  • Keep your skin clean with warm water, gentle soap, and soft towels.
  • Moisturize your skin with a healthcare provider-recommended moisturizer.
  • Protect your skin with soft, comfortable clothing that is not too tight.
  • Stay out of the sun as much as possible, and wear sunscreen with an SPF of 30 or higher daily.

Complications

See a healthcare provider right away if you notice any of the following with the rash:

  • The rash has spread all over your body, especially if it spreads quickly.
  • The rash hurts.
  • The rash has turned to blisters.
  • The rash is swollen and warm to the touch.
  • The rash becomes infected. 
  • There is a red streak around the rash.
  • You're having trouble breathing.
  • You have a fever.

Additionally, there are complications with leukemia itself. You may be at risk for developing infections or other cancers if you have leukemia.

You might also experience tumor lysis syndrome (TLS)—a complication from chemotherapy where more potassium, phosphorus, and uric acid are released into the bloodstream. Another complication is disseminated intravascular coagulation (DIC), a condition where you might experience thrombosis (blood clotting) and hemorrhage.

A Quick Review

A leukemia rash may develop due to the cancer spreading to the skin or in response to treatments. Leukemia rashes are rare, and most rashes do not result from leukemia. Consult a healthcare provider if you have an unexplained rash. Tests like blood tests and imaging can determine if leukemia is possible.

Notify a healthcare provider right away if you have leukemia or another type of blood cancer and develop a rash. They may need to update your treatment regimen. 

Frequently Asked Questions

  • What do tiny red leukemia spots look like?

    The tiny spots can appear red on lighter skin and dark red on darker skin.

  • How do you know if petechiae is leukemia?

    Petechiae potentially associated with leukemia will not turn white if you press down on the tiny spots.

  • Where does petechiae start with leukemia?

    A person with leukemia may have petechiae that's widespread or on their arms, legs, and torso.

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19 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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