What causes petechiae? Related conditions and treatments

Medically reviewed by Anne JacobsonMD, MPH
Board-Certified Family Physician
Updated May. 7, 2024  •  Published Oct. 23, 2023
Fact Checked
 What causes petechiae?

Overview: What do petechiae look like?

Petechiae (pronounced “puh-tee-kee-aye”) are pinpoint red, purple, or brown spots on the skin or the mouth. They’re small (less than 2 mm), round, and flat. A cluster of petechiae often resembles a rash, but it isn’t. Instead, petechiae are tiny bruises that form when small blood vessels in the skin or mucous membranes break or leak. The lesions are the tiny amount of blood that leaks into the surrounding skin tissue. Unlike a rash, petechiae are non-blanchable; when pushed down, they don’t turn pale but keep their original color. Petechiae aren’t painful or itchy. They usually don’t feel like anything. Though any part of the skin can be affected, petechiae most commonly appears on the arms, legs, stomach, mouth, buttocks, and eyelids. However, sometimes petechiae can cover the skin on the entire body. There are many possible causes of petechiae. However, all instances of petechiae are due to one of two major reasons: either there’s damage to blood vessel walls, or the body can’t form blood clots effectively.

Key takeaways:

  • Petechiae are a common symptom that may be caused by bacterial infections, viral infections, injury, blood vessel disorders, inflammatory conditions, blood disorders, cancer, nutritional deficiencies, chronic liver disease, medication side effects, or prolonged straining, lifting, or pushing.

  • Typically, petechiae do not require immediate medical attention unless the spots spread rapidly or there are other severe symptoms such as fever, changes in mental status, or difficulty breathing.

  • Petechiae may or may not require treatment. It depends on other symptoms and how rapidly the spots spread. Petechiae resolves without treatment in many cases. If treatment is needed, petechiae resolves when the underlying condition has been addressed. 

  • Treatments of petechiae vary by cause. Read more here about treatments for mononucleosis, leukemia, strep throat, and lupus.

  • Petechiae often can be managed with rest, fluids, and cold compresses.

  • Save on prescriptions for conditions that may cause petechiae with a SingleCare prescription discount card.

What causes petechiae?

Petechiae have many causes. Most are relatively harmless, such as skin injury or straining. Although there are many causes, petechiae form when the body cannot form blood clots or when blood vessels are damaged.

Common but harmless petechiae causes include:

Other causes of petechiae that often require evaluation and treatment include:

  • Viral infections such as mononucleosis, cytomegalovirus (CMV), hantavirus, enterovirus, influenza, Epstein-Barr virus (EBV), and parvovirus B19 (“fifth disease”)

  • Viral bleeding diseases (“viral hemorrhagic fevers”) such as dengue and Ebola

  • Bacterial infections such as strep throat, meningococcal disease, scarlet fever, heart infection (endocarditis), sepsis, and Rocky Mountain spotted fever (RSMF or rickettsia)

  • Fungal infections

  • Vitamin C deficiency (scurvy) or vitamin K deficiency

  • Severe injury such as car accidents or asphyxiation

  • Leukemia

  • Bone marrow failure

  • Low platelet levels in the blood (thrombocytopenia)

  • Blood clotting or bleeding disorders (idiopathic thrombocytopenic purpura or disseminated intravascular coagulation)

  • Blood vessel swelling (vasculitis) such as Henoch-Schonlein purpura (more common in children)

  • Systemic lupus erythematosus (SLE)

  • Chronic liver disease

  • Some rare connective tissue or congenital disorders

Petechiae can be a sign of a serious condition. But most of the serious conditions on this list will also have other symptoms, such as fever, fatigue, bleeding, or a change in mental status.

Should I be worried about petechiae?

Many people who notice petechiae in themselves or their children are alarmed. While most causes of petechiae are harmless, it can be a sign of a very serious or even life-threatening illness such as a brain infection. If unexplained red spots are causing worry, call a healthcare professional for medical advice. 

It’s important to consider petechiae in relation to other symptoms. If there are no other symptoms and the spots are not spreading, immediate medical care is probably unnecessary. Call a healthcare professional for medical advice if there’s any confusion about the cause. See a healthcare provider if there are other symptoms, the spots cover the whole body, or the spots are spreading. If there are severe symptoms or the spots are spreading quickly, call 911 or go to an emergency room.

Severe symptoms that may be associated with petechiae include:

  • Shortness of breath

  • Trouble breathing

  • Bruising or bleeding

  • Changes in mental status like fainting, confusion, sleepiness, disorientation, or dizziness

  • High fever

How is the cause of petechiae diagnosed?

Petechiae are a symptom, not a disease. Treatment is aimed at the underlying cause. To diagnose, a clinician will take a complete history, review other symptoms, examine the spots, and perform a physical examination. 

The clinician will note the extent of the petechiae and what parts of the skin are affected. Petechiae on the upper body or inside the mouth tells a different story than petechiae on the stomach or legs. The clinician will note other types of bruising. Petechiae are tiny, pinpoint bruises, but the clinician will look for larger bruises, too. Bruising between about one-tenth of an inch (4 mm) to ½ inch (1 cm) is called purpura. What we would typically call a bruise—one that is bigger than 1 cm—is called an ecchymosis (pronounced “e-chuh-moe-sus”). The types and extent of bruising can point to possible causes.

Depending on the whole clinical picture, the clinician may need to perform blood tests, take X-rays or a CT scan, and possibly test for bacteria or viruses. In many cases, the clinician will test how well blood clots form.

Before talking to a clinician, get ready to answer questions such as:

  • When did the spots appear?

  • What happened before they appeared?

  • Have the spots been spreading?

  • Are there other symptoms?

  • Do you have other medical conditions?

  • What medications are being taken?

Are petechiae contagious? 

Petechiae are not contagious. People cannot “catch” bruises by coming in contact with them. Many causes of petechiae are not infectious, either.

However, petechiae can be a sign that someone has a contagious disease, particularly in a child. Petechiae are a more common response to viral infections in children than in adults. If petechiae are caused by infection, there will be other signs besides red spots, such as fever. 

How long do petechiae last?

Petechiae can last for any amount of time. It depends on the type and severity of the underlying condition. If petechiae are caused by minor problems like skin injury or a mild infection, they typically clear up on their own in a few days. However, some underlying causes are chronic medical conditions. In those situations, petechiae may come and go.

How to stop petechiae

There is no specific treatment for petechiae. Instead, healthcare professionals focus on the underlying condition, so treatments vary.

  • For petechiae caused by a minor injury, the standard treatment is to let the capillary damage heal.

  • Viral infections are often only treatable with rest and supportive care.

  • Petechiae due to medication side effects may be handled by stopping the medication. But some medications, like blood thinners, may need to be continued for other reasons.

  • Vitamin C or vitamin K deficiency can be addressed with dietary changes or supplements.

  • Antibiotics will be used to treat bacterial infections.

  • Corticosteroids or immune suppressants will be used to treat autoimmune diseases or blood vessel inflammation.

  • Leukemia is treated with chemotherapy, targeted therapy, immunotherapy, radiation therapy, and bone marrow transplants.

Living with petechiae 

Petechiae are tiny bruises, so there’s not much people can do at home to treat the spots other than prevent further bruising. Some at-home remedies that may help include:

  • Infection prevention through measures such as frequent handwashing, good sanitary practices, and avoiding people with infections

  • Injury prevention by wearing protective clothing and sunscreen, avoiding risky situations and using insect repellent to prevent bug bites

  • Cold compresses to reduce swelling

  • Drinking fluids

  • Rest

Most importantly, don’t panic unless there are other serious symptoms

The sudden appearance of red or purple spots of any size on the skin can be alarming. Most of the time, it’s nothing to panic about. The red spots are probably not an ominous sign if no other symptoms exist. Ask yourself a few questions: Did you get sunburned? Were you straining at some point, like lifting a heavy box? Are you taking medications that cause bleeding, like aspirin or ibuprofen? But if there are other symptoms, especially serious ones, see a healthcare professional right away. 

What’s next? Additional resources for people with petechiae

Test and diagnostics

Treatments

Scientific studies and clinical trials

Medically reviewed by Anne JacobsonMD, MPH
Board-Certified Family Physician

Anne Jacobson, MD, MPH, is a board-certified family physician, writer, editor, teacher, and consultant. She is a graduate of University of Wisconsin School of Medicine and Public Health, and trained at West Suburban Family Medicine in Oak Park, Illinois. She later completed a fellowship in community medicine at PCC Community Wellness and a master's in Public Health at the University of Illinois-Chicago. She lives with her family near Chicago.

...