Appearance | Where They Appear | Causes | Diagnosis | Management | Support

Petechiae are pinpoint-shaped spots of blood that form under the skin. Although leukemia isn’t the only possible cause of petechiae, the skin symptom is very common among people who have this form of blood cancer. Research suggests that leukemids — nonleukemic skin signs of leukemia, including petechiae — may occur in more than 40 percent of people who have leukemia.

This article covers the basics of what petechiae are, why they form, and how you can manage them.

What Do Petechiae Look Like?

Petechiae are tiny, round spots on the skin that appear to be red, purple, or brown. These spots are usually flat and often develop in clusters. At a distance, these qualities can make petechiae appear as a skin rash, although the marks usually do not cause itching or inflammation

Petechiae are nonblanching, which means that they don’t lighten in color when you apply pressure to them. Notably, all petechiae are smaller than 2 millimeters in size — those that grow bigger are known as purpura. Usually, marks of either size form and fade within a few days.

Where Do Petechiae Most Often Appear?

Petechiae can form anywhere on the body, although they often appear on the arms, legs, and trunk (torso). They may sometimes be mistaken for a rash. As one MyLeukemiaTeam member with chronic lymphocytic leukemia (CLL) wrote, “I’ve been having a rash that comes and goes, mostly on my arms and torso.” Another member was unsure what the symptom was, writing, “I get these red dots and blemishes on my torso, arms, and for some strange reason, my right leg.”

Petechiae can occur on the extremities, too. “Mine’s mostly on my legs and feet,” one member with the symptom noted.

More rarely, petechiae might form on the eyelids or in the mucous membrane of the mouth. Petechiae that develop in the nail bed are known as “splinter hemorrhages” because of their appearance. Instead of forming into tiny circles, they develop into straight, reddish discolorations under the nail plate.

What Causes Petechiae?

Petechiae form when capillaries (tiny blood vessels) break and allow trace amounts of blood to leak into the skin. In a healthy person, petechiae might occur after a period of prolonged straining. Common situations that might lead to petechiae formation include weightlifting, intense coughing, and giving birth. Some infections (such as strep throat or mononucleosis), as well as deficiencies in vitamins C or K, can also lead to petechiae.

What Causes Petechiae in Leukemia?

Leukemia is a blood cancer that occurs when the DNA of an immature red blood cell or white blood cell within a person’s bone marrow mutates. When that cell duplicates, it copies the mutated DNA into additional cancer cells. Over time, this replication causes dysfunction in a person’s circulatory and immune systems by suppressing the development of normal cells. It also leads to the signs and symptoms associated with leukemia, including petechiae.

Petechiae are considered a nonleukemic manifestation of leukemia, meaning that although petechiae and purpura can occur with leukemia, the skin marks are not directly related to the cell mutation that causes the underlying cancer. Instead, they are related to thrombocytopenia.

Thrombocytopenia

For someone with leukemia, the root cause of petechiae is usually symptoms of thrombocytopenia, or a low platelet count in the blood. “When my platelets are even the slightest bit low, I get petechiae all over,” one MyLeukemiaTeam member commented.

Platelets (also called thrombocytes) are clotting agents. Normally, these blood cells clump together to plug breaks in blood vessels and to prevent further bleeding after an injury. But this process requires a certain number of platelets to function. A person with thrombocytopenia has fewer than 150,000 platelets per microliter of blood.

When and why a person with leukemia develops thrombocytopenia can vary depending on their specific diagnosis and treatment plan. For example, those with acute myeloid leukemia or acute lymphoblastic leukemia generally develop thrombocytopenia fairly quickly. Petechiae might even be one of their first signs of leukemia.

However, those with chronic myeloid leukemia usually initially experience elevated platelet counts. They typically wouldn’t develop thrombocytopenia until they reached the accelerated (or “blastic”) stages of disease progression, during which dysfunctional leukemia cells (blasts) have infiltrated the bone marrow and caused enough buildup to stall proper platelet production.

Chemotherapy Drugs

Another potential cause of thrombocytopenia — and, by extension, petechiae — are chemotherapy drugs. “Shortly after a chemo run, I got a rash on my entire body,” a MyLeukemiaTeam member said, sharing a snapshot of petechiae on their legs.

People with acute leukemia are often treated with drugs to kill dysfunctional cells. Although this approach can facilitate remission, it can also reduce bone marrow productivity and lead to low platelet counts as side effects. Once treated, it may take a few weeks for someone with leukemia to regenerate healthy bone marrow and start producing platelets at normal levels again. As such, a person with leukemia may see petechiae form more frequently after a round of chemotherapy.

Diagnosing Petechiae

Usually, a physician can diagnose petechiae with a simple visual exam. However, because the potential causes for petechiae vary so widely, your doctor will likely need to ask a few questions about your medical history, other symptoms, and recent activities to figure out the underlying cause.

If you haven’t already been diagnosed with leukemia, your doctor may check for a few telltale signs of leukemia, such as anemia or swollen lymph nodes.

If leukemia is suspected as the root cause of your petechiae, your primary care doctor will be able to refer you to an oncologist who can talk through your treatment options and what you can expect from the treatment process. They may also conduct blood tests to check your total platelet count and assess your blood cell health or take a bone marrow biopsy to search for hidden leukemia cells. A biopsy can also help your oncologist figure out which type of cancer you have. There are several subtypes of leukemia, all of which require specific treatment regimens.

Managing Petechiae From Leukemia

Because petechiae are not actively harmful, there aren’t all that many direct therapies you can apply to make them fade more quickly. “I did not have any treatment, and they are going away,” a MyLeukemiaTeam member said of their petechiae.

There are a few steps you can take to manage petechiae. The first step is to treat your underlying leukemia.

Treating Your Leukemia

If cancer is causing thrombocytopenia, petechiae will continue appearing until your platelet count increases to normal clotting levels. Once your leukemia goes into remission, your bone marrow will have a chance to grow back and start producing platelets.

Meet Your Team

Dealing with leukemia can be intimidating and stressful. Having someone who truly understands what you’re going through can be invaluable. Luckily, that kind of support isn’t far out of reach. MyLeukemiaTeam is a social media platform designed and built for people with leukemia. Members come together to share stories, ask questions, and provide insights. You can step into a thriving, supportive community — all you need to do is sign up.

Do you have any tips on how to deal with petechiae? Leave a note in the comment section below or start a conversation by posting on MyLeukemiaTeam.