What Are Petechiae and Why Do They Appear?

Petechiae are skin lesions that can appear for multiple reasons. Fortunately, they're benign in most cases. However, they can be a symptom of severe conditions.
What Are Petechiae and Why Do They Appear?

Last update: 07 June, 2023

The skin is usually a reflection of the general state of health. In this sense, changes in skin color, as well as the presence of vesicles, blisters, scabs, or petechiae may indicate that something is wrong. Are you interested in knowing what petechiae are and why they appear?

Petechiae are usually a symptom that varies in intensity according to the underlying cause. In general, they’re part of the group of common exanthematic diseases during childhood. Similarly, the appearance of these lesions in adults can be associated with the consumption of certain medications or the presence of risky systemic pathologies.

What are petechiae?

Petechiae are small, pinpoint red spots that appear on the skin as a result of bleeding. These lesions vary in size from 1 to 2 millimeters and sometimes resemble a pinhead. However, they can also take on a bright red, burgundy, purple, or brown tone, depending on the etiology and the time of evolution.

The lesions are usually localized in small groups or can be distributed along the face, thorax, arms, and legs. These small skin bleeds are generally not raised and are flat to the touch. In addition, they’re characterized by not disappearing under direct pressure.

Why do petechiae appear?

The small-caliber blood vessels or capillaries are responsible for nourishing the different layers of the skin, as well as favoring the control of body temperature. Petechiae are the result of the rupture or injury of the capillaries, with the consequent leakage of blood under the skin surface.

The causes of petechiae can range from low-risk conditions to serious, life-threatening conditions. Among the main causes of these skin lesions, the following stand out.


Activities that place excessive and prolonged exertion on the body can promote the appearance of petechiae. They generally develop after an increase in internal pressure due to pushing and overexertion.

In this sense, its appearance is frequent in episodes of intense coughing, continuous vomiting, rectal urgency, weight lifting, and during vaginal birth.

Cough that generates petechiae.
Intense coughing episodes can produce petechiae due to rupture of the small vessels on exertion.

Older people may have various age spots or petechiae on the skin of their face and neck. They’re usually the result of increased fragility of the capillaries and the progressive degeneration of the connective tissue of the dermis. Also, these red spots on the skin are stimulated by chronic sun exposure and drug use.

Sunburns and insect bites

Sunburn is common in fair-skinned people. These injuries are the result of continuous and excessive exposure to the sun’s rays. In addition, they’re characterized by having areas of reddened skin that are sensitive to the touch.

Similarly, studies affirm that the deficiency in porphyrin metabolism in children conditions the appearance of petechiae on the face due to sun exposure. On the other hand, insect bites can cause inflammation and rupture of the small blood vessels in the skin.


Some drugs can cause hematological alterations as an adverse effect. Studies reveal that bone marrow depression and the destruction of a large number of circulating platelets lead to capillary fragility and bleeding.

Among the medications related to the appearance of petechiae are the following:

  • Penicillin
  • Quinine
  • Phenytoin
  • Sulfamides
  • Quinidine
  • Furosemide
  • Linezolid.
  • Non-steroidal anti-inflammatory drugs (NSAIDs)

Infectious diseases

Most infectious diseases of viral origin in children and newborns appear with generalized maculopapular eruptions. Measles, rubella, chicken pox, and roseola are some of the most common rash conditions. In addition, mononucleosis is also associated with the appearance of petechiae that cover the palms and soles for 2 to 3 weeks.

On the other hand, scarlet fever caused by streptococci can manifest with fever and tongue swelling accompanied by a large number of pinpoint spots that line the chest and extremities. Similarly, petechiae are usually warning signs in febrile hemorrhagic diseases, such as dengue and yellow fever.


Meningococcemia is a systemic disease caused by the bacteria Neisseria meningitidis. This occurs with meningitis, a hematogenous spread of the meningococcus, and alterations in integrity of the blood vessels.

The main symptoms of this condition include a stiff neck, fever, and headaches, as well as the presence of petechiae and ecchymoses on the legs and feet.

Vitamin K and C deficiency

Vitamin K is an essential molecule for the synthesis of coagulation factors V, VII, IX, and X. The reduction in the levels of this substance in newborns is associated with an increased risk of hemorrhagic disease. Some research suggests that vitamin K deficiency in neonates has a prevalence of 0.25 to 1.7%.

The clinical manifestations of this disease include melena, rectal bleeding, ecchymosis, petechiae, and bleeding from the umbilical cord. On the other hand, vitamin C deficiency can trigger scurvy, a disorder characterized by bleeding gums, bruising, fatigue, and micro-pinpoint hemorrhages in the skin.


Thrombocytopenia is the medical term for a significant reduction in the platelet count. Platelets are the blood particles responsible for forming small plugs in blood vessel lesions to stop bleeding. For this reason, the decrease in this group favors bleeding and the appearance of multiple petechiae on the skin.

Medullary aplasia, cirrhosis, vitamin B12 deficiency, and some viral infections are common causes of thrombocytopenia. Similarly, thrombocytopenic purpura is a disease that describes the destruction of platelets by the immune system itself.

Endocarditis and septicemia

Endocarditis is the inflammation of the inner lining of the heart that’s often accompanied by conditions of the heart valves. This disease is caused by pathogenic microorganisms that enter the bloodstream through catheters or dental procedures. Classic symptoms include chest pain, shortness of breath, fatigue, and swelling of the feet.

Some people may develop small red or purple petechiae on the skin and inside the mouth. Also, Janeway lesions are common in severe endocarditis. They’re red spots that appear on the soles of the feet and on the palms of the hands.

On the other hand, septicemia is the systemic response to the presence of a pathogen in the blood. This entity is usually accompanied by fever or hypothermia, an accelerated heart rate, and respiratory distress. The development of petechiae, ecchymoses, reddish papules, and pustules is very common in the most severe infections.

Endocarditis causing petechiae.
Endocarditis is an inflammation in the inner layer of the heart that alters the circulatory system, which can lead to petechiae.


Leukemia is the term that describes a group of malignant white blood cell diseases. Studies affirm that the abnormal growth of leukocytes, with the consequent medullary invasion, is responsible for anemia and thrombocytopenia in affected people. This alteration compromises vascular integrity and favors the appearance of petechiae.


Vasculitis is an inflammatory disorder of the walls of the blood vessels. It can affect the arteries of medium and large caliber, as well as the capillaries and veins. The reduction in vascular lumen compromises blood flow to organs and tissues, favoring their dysfunction.

This disease can affect a part of the body or the whole organism in the form of systemic vasculitis. Sometimes, it can present as cutaneous vasculitis, damaging the blood vessels that irrigate the skin, without injuring the internal organs. The alteration of the skin promotes the appearance of multiple purple bruises and purplish petechiae on the legs.

Petechiae are a symptom that shouldn’t be underestimated

Petechiae are small reddish or purple spots that reflect the breakdown or injury of the skin’s capillaries. These are usually associated with benign conditions in most cases.

They’re also a warning sign of active bleeding due to alteration of the vascular structure and lack of platelet compensation. For this reason, professionals recommend immediate medical consultation in the presence of petechiae on the skin. Only in this way can an accurate diagnosis be made.

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