Petechiae
Petechiae are small, flat, red, purple, or brown spots that show up on the skin when tiny blood vessels called capillaries break and bleed underneath. These pinpoint spots can look alarming, but they are usually painless and don’t itch. Petechiae are not a disease by themselves—they signal that something else is happening in the body.
Many things can cause petechiae. Some causes are minor, like a strong cough or minor injury, but others can be more serious, such as infections, side effects of medications, or certain diseases. Petechiae can appear anywhere on the body, including the arms, legs, and even inside the mouth. Knowing what petechiae look like and what can cause them helps people decide when to watch and when to seek medical advice.
What Is Petechiae?
Petechiae are small, pinpoint spots that appear on the skin or inside the mouth. They form when very small blood vessels bleed and can signal various underlying health issues.
Definition and Key Characteristics
Petechiae are tiny, flat spots, less than 2 millimeters in size. These pinpoint dots appear red, purple, or brown and result from bleeding under the skin when capillaries, the smallest blood vessels, break and leak a small amount of blood.
Unlike raised bumps, petechiae are flat to the touch. The spots usually appear in clusters and do not itch or cause pain. They also do not change color when pressed—a key feature used to identify them.
Difference Between Petechiae and Rash
Petechiae and rashes can look similar at first, but they have important differences. Petechiae are small, round, and flat spots that come from bleeding under the skin, while rashes usually involve irritation, bumps, or changes in the texture of the skin.
A key way to tell them apart is by pressing on the spots. Petechiae do not fade when pressed, but most regular rashes will lose some color with pressure. Petechiae do not cause itching or pain on their own, unlike some skin rashes that can be both itchy and uncomfortable.
Common Locations on the Body
Petechiae can show up almost anywhere but most often appear on the arms, legs, stomach, chest, and buttocks. They may also show inside the mouth, especially on the roof or inside the cheeks, and sometimes on the eyelids.
Certain physical actions, such as coughing, vomiting, or injury, can cause petechiae on the face or neck. Infections or blood disorders may make the spots appear in larger areas, sometimes spreading across big sections of skin within a short period.
Noting the location of petechiae helps healthcare providers find the cause. For example, spots on the lower legs often link with blood flow issues, while sudden widespread petechiae may signal a medical emergency.
How Petechiae Develops
Petechiae form when tiny blood vessels called capillaries break and leak blood under the skin. This leakage creates small, round spots that are usually red, purple, or brown in color. Common causes of capillary damage include:
- Physical injury or trauma
- Infections
- Certain medications
- Medical conditions that affect blood clotting
If blood does not clot properly, more bleeding can happen under the skin. Problems like a low platelet count or other bleeding disorders raise the chance of petechiae. Platelets help form blood clots and stop leaks in blood vessels.
Petechiae are different from a simple bruise or purpura. While bruises are usually larger and come from more obvious injuries, petechiae are smaller and often appear in clusters. Below is a table highlighting the main differences:
| Feature | Petechiae | Purpura | Bruise |
|---|---|---|---|
| Size | < 2 mm | 2-10 mm | > 10 mm |
| Cause | Capillary leak | Larger vessel | Usually trauma |
| Appearance | Tiny dots | Larger spots | Blotchy patch |
Problems with platelets or blood vessels can cause these pinpoint spots even without a clear injury. Conditions that affect blood clotting also increase the risk.
Symptoms Associated with Petechiae
Petechiae are tiny spots that can show up for many reasons. Some cases are harmless, while others signal a serious health concern, especially if there are other symptoms with the spots.
How Petechiae Appear and Feel
Petechiae are small, round spots that look red, purple, or brown. They are usually about the size of a pinhead (1–2 mm wide). These dots are flat and do not blanch, meaning they stay visible when pressed with a finger or glass. Unlike many types of rash, petechiae do not itch and are not raised.
They often appear in groups and can show up anywhere on the skin, often on the legs, arms, stomach, or inside the mouth. Most people do not feel them, and there is no pain or irritation on the affected area. Petechiae may be the only finding, or they may appear along with other symptoms, so careful observation is key.
Other Warning Signs
Petechiae can be the first sign of a health problem.
If petechiae appear with other warning signs, the risk of a serious cause increases.
Watch for Symptoms
- Fever (with or without chills)
- Fatigue
- Confusion or new trouble thinking clearly
- Dizziness or fainting spells
- Shortness of breath or trouble breathing
- Unusual bleeding (nose, gums, urine, stool)
- Bruising easily or a rash that spreads quickly
These signs, when combined with petechiae, can point to more dangerous problems, like infections, blood disorders, or reactions to medications.
Do not ignore these symptoms, especially if they get worse.
When to Seek Urgent Medical Attention
Some cases of petechiae require immediate medical care. If you have petechiae with any of the symptoms below, get help right away:
- Sudden fever with rapidly spreading spots
- Loss of consciousness or severe confusion
- Difficult or rapid breathing
- Heavy bleeding or large, unexplained bruises
- Ongoing dizziness or trouble staying awake
These signs can point to a medical emergency, such as a serious infection or bleeding problem. Get medical help as soon as possible if you notice a rapid change in health along with petechiae. If you are unsure, contact a health professional or call emergency services.
