Petechiae are tiny flat spots 1 to 2 millimeters across that look like pinpricks of red, purple, or dark pigment on the skin. They form when the smallest blood vessels, called capillaries, leak a small amount of blood into the surrounding tissue, and the blood stays trapped because it has nowhere to go.
Unlike a rash or a hive, these spots do not blanch, so they keep their color when you press a finger or a clear glass firmly against them. That single visual clue, a non-blanching pinpoint mark, is the most reliable way to recognize what you’re seeing.
This article breaks down the visual cues that distinguish petechiae from rashes, bruises, and bug bites, helping anyone staring at unexpected pinpoint marks figure out what they’re looking at.
The Visual Signature of Petechiae
Spotting petechiae comes down to four traits that, once you’ve seen them together, are hard to mistake for anything else. Run your eye over a patch and these details stand out.
Size, Color, and Texture
Each individual mark measures about 1 to 2 millimeters, often described as pinpoint or as small as the head of a pin. Clusters can spread across a palm-sized patch or march in a line along a skin crease where pressure concentrated.
Fresh spots tend to look vivid red, brick, or bright purple; over the next few days the trapped blood breaks down, and the same spot can shift to a darker purple, rust, brown, or greenish-yellow tint before fading. The surface stays completely flat. There is no raised bump, no fluid-filled blister, no ring, and no scaling, which separates these hemorrhagic spots from most allergic reactions or insect bites.
The Non-Blanching Press Test
Press the pad of a clear finger or a glass tumbler firmly against the spot and hold it for a few seconds. A regular rash flushes white under pressure because the blood in dilated surface vessels simply moves aside. Capillary bleeding does not move, so the color holds. A spot that stays red, purple, or dark while everything around it briefly whitens meets the textbook definition of petechiae.
This single test is the fastest bedside screen a parent or partner can run, and dermatology resources from the American Academy of Dermatology describe it as a core diagnostic step.
Tip: Photograph the area under steady daylight before pressing, then again a few seconds after releasing. Side-by-side shots help a clinician judge whether color persisted.
How Petechiae Differ From Rashes, Bruises, and Bites
The first time most people notice these spots, they wonder whether it’s a rash, an allergic reaction, or simply a bruise from bumping into something. A close comparison clears up the confusion quickly, because each condition lives on a different size scale and responds differently to pressure.
A Size-to-Condition Reference
| Finding | Size | Blanching | Texture |
|---|---|---|---|
| Petechiae | 1 to 2 mm, pinpoint | No, color persists | Completely flat |
| Purpura | 3 to 10 mm, patch-like | No | Flat, may merge into plaques |
| Ecchymosis (bruise) | Greater than 10 mm, broad | No | Flat, tender, color shifts over days |
| Allergic hives | Variable, often raised rings | Yes, briefly white | Raised welts, itchy |
| Heat or viral rash | Variable, clustered | Yes | Flat or finely bumpy, often itchy |
Why Cherry Angiomas and Spider Angiomas Are Different
Bright-red, dome-shaped cherry angiomas commonly dot the trunks of adults past 30, whereas spider angiomas send out radiating legs from a single central point. Both are vascular lesions, meaning they involve dilated blood vessels, but neither is caused by blood leaking out of capillaries into the skin. They tend to blanch at least partially and grow slowly over years, so an urgent rash that appeared overnight is almost never one of these.
Red flag: When pinpoint spots arrive suddenly along with fever, vomiting, confusion, or a stiff neck, treat the combination as a medical emergency and seek evaluation right away. Clusters linked to meningococcemia can spread across the trunk and extremities within hours.
Where Petechiae Typically Appear on the Body
Location matters as much as size, because the pattern often points to the cause. Gravity-dependent areas collect pooling blood most easily, while mechanical triggers land wherever the strain happened.
Lower Legs, Ankles, and Feet
Capillary walls in the lower legs take constant hydrostatic pressure, especially after long periods of standing. Minor leaks show up as scattered pinpoint dots along the shins, around the ankles, or across the tops of the feet. In people with low platelet counts, called thrombocytopenia, the lower legs are usually the first place where new petechiae appear.
Face, Eyelids, and Upper Chest
A forceful coughing fit, an episode of vomiting, weightlifting with a heavy squat, or prolonged retching in childhood can rupture the tiny vessels around the eyes and across the cheeks. The dots cluster around the eyelids and forehead, sometimes trailing down to the upper chest. Childbirth is another classic trigger, and a newborn can arrive with pinpoint spots across the face and scalp simply from the pressure of delivery.
Mucous Membranes as Reliable Checkpoints
Spots inside the mouth, on the soft palate, or along the inner lining of the eyelids reveal the same pinpoint pattern in places where skin tone does not interfere. Because the lining is thin and pale, even a small leak shows up clearly. Clinicians check the conjunctiva and palate first when the diagnosis is uncertain, and you can do the same at home by looking inside the lower eyelid in good light.
How Petechiae Look Across Different Skin Tones
Most reference photos default to lighter skin, which can leave people with deeper complexions wondering whether their spots even qualify. The biology is the same; only the visible color shifts.
Presentation on Deeper Skin Tones
On richly pigmented skin, the same trapped blood often reads as dark purple, deep brown, or near-black dots, and the surrounding skin may show no flush at all. The spots still don’t blanch when pressed, but you may need to look closely or stretch the skin slightly under a strong light to pick them out.
Checking the inside of the lower eyelid, the roof of the mouth, and the sclera of the eye gives a reliable cross-check because those surfaces stay pink or pale regardless of outer tone.
Presentation on Lighter Skin Tones
On pale or fair complexions, fresh spots typically appear vivid red, cherry, or bright pink and stand out clearly against the background. Daylight makes the contrast sharper than indoor bulbs, and a jaundice-yellow cast from certain lights can make old brownish spots harder to see. A quick photo taken next to a white piece of paper gives you a neutral reference for later comparison.
Once you know what to look for on lighter skin, recognizing the same signs on darker tones takes a slightly different visual approach.
Tip: Use natural daylight from a window and avoid camera filters when documenting the spots. Screens and warm bulbs routinely distort both color and size, which can mislead a later phone or telehealth consult.
Common Causes Behind the Spots
Petechiae are a sign, not a disease, and the underlying trigger ranges from completely benign to genuinely urgent. Sorting the causes by mechanism makes the picture easier to hold.
Mechanical and Pressure Triggers
- Violent coughing: A hard coughing bout, especially with whooping cough or a severe asthma flare, routinely produces pinpoint dots around the eyes and upper chest.
- Vomiting or retching: Repeated forceful vomiting in children and adults can rupture facial capillaries within minutes.
- Heavy lifting or straining: Valsalva-style strain during weightlifting, constipation, or childbirth puts sudden pressure on the upper-body vessels.
- Birth pressure: Newborns often show pinpoint spots on the head, neck, and face after a vaginal delivery; most fade within a week.
- Tight clothing or straps: A tourniquet-style cuff, a tight backpack strap, or even a prolonged carry can leave a band of pinpoint marks along the pressure line.
Infections, Nutritional Gaps, and Medications
Common viral illnesses, including dengue fever and several childhood exanthems, list petechiae among their possible skin findings. Bacterial sepsis, especially meningococcemia, can produce a rapidly spreading petechial rash that becomes a true emergency. Vitamin K deficiency, particularly in newborns or people with fat malabsorption, weakens clotting and lets capillaries leak more easily. Medications that thin the blood or suppress platelets, ranging from aspirin to prescription anticoagulants, raise the risk of spontaneous petechiae, especially on the lower legs.
When in doubt, the MedlinePlus drug information sheets list petechiae as a side effect worth reporting.
Platelet and Bone Marrow Conditions
Low platelet counts from immune thrombocytopenia, leukemia, or aplastic anemia often announce themselves through widespread pinpoint bleeding, sometimes paired with bleeding gums, heavy periods, or easy bruising. Vasculitis, an inflammation of small vessel walls, can produce palpable purpura, which are larger raised patches, alongside pinpoint dots. Any sudden appearance across more than one body region deserves a same-day clinical evaluation.
Reading the Spots for Urgency and Next Steps
Tying visual cues to action levels turns a scary skin finding into a calm triage decision. The framework below distills what dermatology and emergency-medicine references recommend.
A Three-Tier Decision Framework
- Monitor at home: A small cluster limited to the face after coughing or vomiting, no fever, no lethargy, and the child or adult otherwise behaving normally. Photograph daily and watch for fading over 3 to 5 days.
- Same-day clinician visit: Spots that spread to new areas within 24 hours, appear on the lower legs without an obvious mechanical trigger, or come with fatigue, bruising, or bleeding gums. A platelet count and basic blood work can sort out the cause quickly.
- Emergency evaluation: Rapid spread across the trunk, accompanying fever, stiff neck, photophobia, vomiting, confusion, cold extremities, or a child who looks drowsy or limp. The combination of petechiae plus fever is a textbook emergency flag because of meningococcal sepsis risk.
What to Document Before Calling
Snap a photo under daylight, note the time the spots first appeared, and track any new spots over the next several hours by marking them lightly with a washable pen or taking timestamped photos. List recent activities: a coughing fit, a new medication, a long hike, or a recent viral illness. Bring the medication list and the photo timeline to the visit.
Clinicians, especially those doing telehealth through services aligned with National Institutes of Health guidance, can often narrow the cause dramatically with that information alone.
With those urgency signals in mind, here is what to carry away from the entire guide.
Reassuring sign: A small patch of pinpoint dots that appeared after a clear mechanical trigger, fades toward brown within a few days, and is not accompanied by fever or bleeding elsewhere usually reflects a benign capillary rupture that needs no treatment beyond watchful waiting.
Bottom Line
Petechiae are tiny, flat, pinpoint spots that stay colored under pressure and appear when capillaries leak small amounts of blood into the skin. Size, color, location, and the non-blanching test together separate them from rashes, bruises, and bites, while the pattern across the body and the company the spots keep, such as fever, lethargy, or bleeding elsewhere, sets the urgency.
Run the press test, photograph what you see, and move up the action ladder whenever the spread accelerates or systemic symptoms join the picture.
FAQ
Are petechiae raised or flat?
A glass slide pressed flat against the skin reveals no swelling or elevation in true petechiae. There is no bump, blister, or swelling at the spot itself, which is one of the clearest ways to separate them from allergic welts, insect bites, or hives.
What color are petechiae spots?
Fresh spots look bright red, cherry, or pink on lighter skin and dark purple, deep brown, or near-black on deeper skin tones. As the trapped blood breaks down over several days, the color shifts toward rust, greenish-yellow, or light brown before fading.
Do petechiae blanch when pressed?
Press a clear glass against the spots and the color stays put, confirming that petechiae fail to fade under pressure. Pressing a clear glass or finger over the spot leaves the color intact because the blood is trapped outside the vessels. Ordinary rashes and hives briefly whiten under the same pressure.
When should I worry about petechiae?
Seek same-day or emergency care when the spots spread quickly, cover more than one body region, or arrive alongside fever, stiff neck, confusion, vomiting, drowsiness, or bleeding from the gums or nose. Sudden widespread pinpoint bleeding in a child is always treated as urgent.
Where do petechiae commonly appear on the body?
They show up most often on the lower legs, ankles, and feet, around the eyes and face after coughing or vomiting, across the upper chest after straining, and inside the mouth or along the inner eyelids regardless of skin tone.
Can petechiae go away on their own?
Yes, individual spots usually fade over 3 to 7 days as the trapped blood breaks down, similar to a small bruise. The underlying cause, however, may still need attention if new spots keep appearing or if other symptoms develop.
