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Petechiae

What Is It, Causes, Treatment, and More

Author: Anna Hernández, MD

Editors: Ahaana Singh, Kelsey LaFayette, BAN, RN 

Illustrator: Abbey Richard

Copyeditor: Joy Mapes

Modified: 4 Jan 2024


What is petechiae?

Petechiae are small, red or purple spots that occur as a result of bleeding into the skin or mucous membranes, which line various cavities in the body, such as the inside of the mouth. In most cases, petechiae are caused by a benign and harmless condition, but in some cases they may be a sign of an underlying disorder that requires urgent attention. Although petechiae can occur at any age, they are more commonly seen in older adults and children.

What causes petechiae?

Petechiae appear due to minor bleeding from tiny blood vessels, known as capillaries, that lie under the skin and mucous membranes. Although there are many causes that can lead to petechiae, the underlying mechanisms typically involve damage to the blood vessel walls that makes the capillaries leak or a low blood platelet count (i.e., thrombocytopenia), which can lead to spontaneous bleeding in the absence of trauma.

Tiny petechiae that appear on the face, neck, and upper chest are often caused by capillaries that rupture due to prolonged straining during a bowel movement or severe bouts of coughing or vomiting. Petechiae may also occur as a result of traumatic injuries, sunburns, or as a side effect of certain medications, such as antibiotics and anticonvulsants. 

In children, infections are a common cause of petechiae. Viruses, like cytomegalovirus (CMV), Epstein-Barr virus (EBV), or influenza; bacteria, including Neisseria meningitidis and group A Streptococcus species; and fungi, such as Candida and Aspergillus species, can all be sources of petechiae-inducing infections. Other, less common infections that can lead to petechiae include Rocky Mountain spotted fever, which is transmitted by a tick bite, and viral hemorrhagic fevers, such as dengue, ebola, and yellow fever. Overall, infections can lead to petechiae through several different mechanisms, including damage to the blood vessel walls, toxin release, or uncontrolled activation of coagulation, which in turn can lead to a low blood platelet count.

Other than certain infections, pathological causes of petechiae include bone marrow failure, which refers to a decreased production of platelets and red and white blood cells; leukemia, which is a type of blood cancer; and other disorders leading to thrombocytopenia, such as immune thrombocytopenic purpura (ITP), hemolytic uremic syndrome (HUS), and disseminated intravascular coagulopathy (DIC). Finally, petechiae may be a sign of systemic conditions, including blood vessel wall inflammation (i.e., vasculitis); connective tissue disorders with increased blood vessel fragility; chronic liver disease; and vitamin C or vitamin K deficiency

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What does petechiae look like?

Petechiae appear as flat, red or purple spots that measure between 1 to 2 millimeters (about 0.04 to 0.08 inches) in diameter. If the same spots are larger than 2 mm, but smaller than 1 centimeter (about a third of an inch), they are called purpura instead. Lesions that are greater than 1 cm are called ecchymoses or bruises. 

Both petechiae and purpura are like tiny versions of bruises, in which a small amount of blood has leaked into the skin and created a visible spot. Characteristically, these spots are non-blanching, meaning they do not become paler when pressed lightly for a few seconds. This can be helpful to differentiate them from other skin lesions, such as allergic skin rashes or spider veins, which fade away and appear whitish when pressure is applied.

How long does petechiae last?

Petechiae can last for a variable amount of time, depending on the underlying cause and severity of the condition. In most cases, petechiae resolve on their own within a few days of onset. In severe cases, or if caused by an underlying pathological condition, petechiae may persist or spread quickly over the entire body until the underlying cause is addressed.  

How is petechiae diagnosed and treated?

Diagnosis of petechiae is based on the observation of non-blanching, pinpoint-sized, red or purple spots. Careful evaluation of any individual with petechiae is essential for early diagnosis and treatment, particularly in children who appear unwell and present with signs of infection. In such cases, a very serious condition known as meningococcemia, a widespread infection by Neisseria meningitidis, should be suspected and treated urgently. 

After a thorough medical history and physical exam, further assessment depends on the clinical suspicion and may include blood tests, microbiological cultures, or imaging techniques, such as an X-ray or computerized tomography (CT) scan. 

Treatment is aimed at resolving the underlying cause of petechiae. In some cases, petechiae may fade away entirely on their own, especially if they were caused by a mild viral infection or minor injury. If induced by medication, petechiae may resolve upon discontinuation of the specific medication.  On the other hand, if petechiae are a result of a bacterial infection, treatment may include broad-spectrum antibiotics, as well as supportive measures and, possibly, hospitalization. Finally, other causes of petechiae may require specific treatments or referral to other medical specialists in order to confirm the diagnosis and treat the underlying condition. 

What are the most important facts to know about petechiae?

Petechiae are non-blanching, red or purple skin spots that measure less than 2 mm in diameter. They occur as a result of minor bleeding from tiny blood vessels that lie under the skin or mucous membranes. Petechiae can be caused by a variety of underlying conditions, including certain medications, traumatic injuries, infections, and blood disorders, among others. Diagnosis of petechiae begins with a thorough medical history and physical examination. Some cases of petechiae may require further diagnostic assessment, such as blood tests, microbiological cultures, or imaging techniques. Treatment of petechiae is aimed at resolving the underlying cause and may vary from simple observation to intensive medical treatment. 

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Related links

Bleeding disorders: Clinical practice
Hemophilia: Nursing process (ADPIE)
Platelet disorders: Pathology review
Thrombocytopenia: Clinical practice

Resources for research and reference

Barnetson, L., Heaton, P., Palmer, S., & Paul, S. (2016). Petechial rash in children: A clinical dilemma. Emergency Nurse, 24(2), 27-35. DOI: 10.7748/en.24.2.27.s25 

Kumar, V., Abbas, A., Aster, J., & Robbins, S. (2013). Robbins basic pathology, (9th ed.). Philadelphia, PA: Elsevier/Saunders.

Raffini, L. (2019). Evaluation of purpura in children. In UpToDate. Retrieved February 17, 2021, from https://www.uptodate.com/contents/evaluation-of-purpura-in-children#H43 

Thomas, A., Baird, S., & Anderson, J. (2016). Purpuric and petechial rashes in adults and children: Initial assessment. BMJ (Clinical research ed.), 352: i1285. DOI: 10.1136/bmj.i1285