If you have leukemia and your damaged white blood cells outnumber healthy ones, you may develop skin symptoms, like rashes, bruising, and mouth sores.

Leukemia is a type of blood cancer that develops in the bone marrow, where blood cells are made. It causes the body to make a large number of abnormal white blood cells.

White blood cells normally protect the body against infection. In leukemia, damaged white blood cells crowd out healthy blood cells, causing skin symptoms.

In 2021, around 508,796 people were living with leukemia in the United States, according to the National Cancer Institute (NCI). Additionally, an estimated amount of 62,770 new cases were predicted for 2024.

In this article, find out more about the skin symptoms leukemia can cause.

Common skin symptoms with leukemia include:

  • petechiae
  • acute myeloid leukemia (AML) rash
  • mouth sores and swollen gums
  • leukemia cutis
  • easy bruising and bleeding
  • changes in skin color
  • other skin infections due to a reduced immune response

Tiny spots called petechiae

One symptom that some people with leukemia might notice is tiny red spots on their skin. These pinpoints of blood are called petechiae. On fair and light skin tones, these may appear as red dots. On darker skin tones, they may be darker than the surrounding skin and less noticeable.

Petechiae usually occurs where blood is most likely to accumulate, such as in your:

  • feet
  • legs
  • hands
  • arms

The spots are caused by tiny broken blood vessels, called capillaries, under the skin. Normally, platelets, the disc-shaped cells in the blood, help your blood clot. But with leukemia, your body does not have enough platelets to seal off the broken blood vessels.

Mouth sores and swollen gums

Mouth sores are common with some types of leukemia. In fact, some researchers say newly appearing mouth ulcers and swollen gums may be an early sign of AML.

These changes may happen because of low levels of white blood cells or anemia.

Leukemia cutis

Leukemia cutis refers to various signs that can occur when leukemia affects your skin. It may appear before, alongside, or after other leukemia symptoms, but experts say it is rare. It happens when leukemia cells travel to the skin.

Symptoms may affect your face, trunk (torso), and extremities and include:

  • changes in skin color
  • plaques (thick patches)
  • ulcers and blisters, in some cases
  • lumps under the skin, known as nodules, that typically feel firm or rubbery
  • small raised bumps on the skin, known as papules, that may feel firm or rubbery

Bruises

A bruise develops when blood vessels under your skin are damaged. People with leukemia are more likely to bruise because their bodies don’t make enough platelets to plug bleeding blood vessels.

Leukemia bruises look like any other kind of bruise, but there tend to be more of them than usual. Additionally, they may show up on unusual areas of your body, such as your back.

Easy bleeding

The same lack of platelets that cause bruising also leads to bleeding. People with leukemia may bleed more than they would expect even from a small injury, such as a tiny cut.

They may also notice bleeding from areas where there is no injury, such as their gums or nose. Injuries often bleed more than normal, and the bleeding may be unusually hard to stop.

Change in skin color

Although leukemia can leave dark-colored rashes or bruises on your body, it can also affect your skin color in other ways.

People with leukemia who have fair skin tones may look pale because of anemia. If you have anemia and you have a darker skin tone, you may notice that the mucous membranes in your mouth, nose, or eyes look blueish or gray.

Anemia is a condition in which your body has a low number of red blood cells. Without enough red blood cells to carry oxygen to the body, anemia can cause symptoms such as:

  • fatigue
  • weakness
  • lightheadedness
  • shortness of breath

If you have leukemia, skin changes can also happen for other reasons, such as an infection or an allergic or sensitivity reaction, for example, to drugs.

When your body cannot produce enough white blood cells, it may become easier for several common infections and other problems to develop. This is because your immune system finds it harder to stop them.

Ringworm and other fungal infections

Leukemia affects the immune system, making it harder to build an immune response against fungal and other infections. Research from 2011 notes that these types of infections can affect people with leukemia in different ways and for different reasons, depending on the type of leukemia and treatment options.

Some fungal infections can become life threatening. It is essential to follow your doctor’s instructions about how to prevent them and what to do if they happen. Fungal infections can include:

  • Ringworm: This is a fungal infection, also called tinea, that can appear on your skin as a circular rash. It is often itchy.
  • Nail infections: An infection that can cause your nails to change color, crack, break, and fall off. It may be linked to a fungal infection on your skin.
  • Candida: Candida is a fungus that lives on your skin and commonly occurs in the mouth, throat, gut, and vagina. It does not usually cause problems, but it can lead to a rash if your immune system is affected by leukemia.

Many types of fungal infections can affect people with leukemia. It’s best to tell your doctor as soon as you notice any changes so they can help you manage them.

Folliculitis

Folliculitis is an infection that affects your hair follicles. It’s usually caused by bacteria, but it can be fungal or viral. If you have a weakened immune system, you may have a higher risk of contracting it.

Depending on the cause, symptoms can include:

  • pustules (small, fluid-filled bumps)
  • itching
  • papules or plaques, in some cases

It can affect the:

  • scalp
  • face
  • neck
  • shoulders

Vasculitis

Vasculitis is an inflammation of small blood vessels and capillaries. If you have leukemia or another condition that affects the immune system, you may have a higher risk of leukocytoclastic vasculitis.

Symptoms include purple or darker areas on the skin, which may feel different to the touch than the surrounding skin. They can range from 1 millimeter to 1 centimeter in diameter.

There may be:

  • pustules
  • bullae, similar to blisters
  • nodules
  • crusted ulcers

There may also be:

  • a low grade fever
  • a general feeling of being unwell
  • body pain

Skin ulceration can occur in some cases. If you notice these types of changes, it is best to speak with your doctor.

Sweet syndrome

This condition can affect people with various conditions, including those with cancer or a weakened immune system. It can result from an infection or from cancer itself. It’s also known as acute febrile neutrophilic dermatosis.

Symptoms include:

  • fever
  • plaques
  • papules
  • arthralgia
  • headaches
  • changes in your skin color
  • possible oral or genital lesions

Skin changes often appear suddenly, and there may also be a fever. Symptoms may go away without treatment, but if you have a diagnosis of leukemia, it is best to ask your doctor’s advice as you may need treatment.

Allergic reactions to treatment

Some drugs can cause skin rashes.

Morbilliform drug eruption is a common immune reaction to prescription drugs. People with a weakened immune system have a higher risk of developing this type of rash.

A rash may appear 1 to 2 weeks after starting a drug, but it can occur up to a week after finishing the medication. If you start taking the drug again, the rash may come back after 1 to 2 days.

The reaction usually:

  • involves papules or flat macules
  • changes in your skin color that may become pale with pressure but regain their color on releasing the pressure
  • starts on your trunk and spreads to both sides of your body, on the limbs and neck

The skin may become pink to red on any skin tone. The changes in color may be harder to see on darker skin, or the pink or red may be darker.

In most cases, complications don’t arise, and the rash goes away after stopping the drug. But it’s important not to stop using any medication without first checking with your doctor.

Chemotherapy, radiation therapy, and other cancer treatments can also cause a rash, dry skin, and other skin changes. Before starting any new treatment, speak with your doctor about what to expect and when to ask for help.

Leukemia has a variety of symptoms, which will depend on the type of leukemia you have. Many of these are caused by a lack of healthy blood cells. In addition to skin symptoms, the American Cancer Society (ACS) lists the following as common symptoms when a person has a low blood cell count:

  • feeling unusually tired or weak
  • feeling dizzy or lightheaded
  • difficulty breathing
  • frequent infections, including fever and chills
  • heavy bleeding during menstruation
  • frequent or severe nosebleeds
  • bleeding gums
  • weight and appetite loss
  • night sweats

Leukemia is not the only possible cause of many of these symptoms, but blood tests and other tests can help your doctor confirm or rule out a diagnosis.

Acute lymphocytic leukemia

Other symptoms of acute lymphocytic leukemia (ALL) include:

  • abdominal swelling, as cancer cells build up in your liver and spleen
  • lymph node swelling, appearing as lumps under your skin, for instance, in your underarms, neck, or groin
  • bone or joint pain
  • a range of other symptoms if leukemia spreads to other areas, such as the lungs or brain

Chronic myeloid leukemia

With chronic myeloid leukemia (CML), symptoms tend to develop more slowly. They include:

  • weakness and fatigue
  • night sweats and fever
  • weight loss
  • bone pain
  • swelling in your spleen, under the left side of your rib cage
  • a feeling of fullness in your abdomen, even after eating just a little

Childhood leukemia

Signs and symptoms specific to childhood leukemia, according to the ACS, include:

  • weakness and tiredness
  • feeling cold
  • dizziness and lightheadedness
  • difficulty breathing
  • changes in skin color; for instance, darker skin may become duskier, and light skin may appear paler

If you have been diagnosed with leukemia, your doctor will tell you what to look for and what to do if you experience symptoms.

If leukemia or your treatment has weakened your immune system, it’s best to seek medical advice as soon as any concerns arise. Your healthcare team can help you manage these symptoms.

If you do not have leukemia, it’s worth remembering that rashes and skin changes can happen for many reasons. However, if other signs are causing concern, ask a doctor to check them out.

Many skin changes improve with treatment, and it can be a good idea to rule out more serious causes.