Petechiae in babies: the tiny red spots that do not fade under pressure
Discovering tiny red or purple spots on your baby's skin is naturally frightening. Most of the time there is a harmless explanation, but a non-blanching rash can also be an early warning sign of a serious infection. Knowing how to check and what to do in each scenario is one of the most important things a parent can have in their back pocket.
What petechiae are
Petechiae (say: puh-TEE-kee-eye) are tiny flat spots caused by very small amounts of bleeding just beneath the surface of the skin. They look like pinprick-sized dots, typically red, purple, or dark brown, and are not raised or bumpy. They appear when tiny blood vessels called capillaries leak a small amount of blood into the surrounding skin.
Petechiae can vary from a few isolated dots to a dense cluster. They do not change colour or fade when you press on them, which is the key feature that sets them apart from most ordinary rashes.
The single most important check: the glass test
Most rashes in babies are caused by dilated blood vessels near the surface of the skin. When you press on them, the blood is pushed aside and the spot temporarily turns white or pale before returning. These rashes are described as "blanching." Petechiae, by contrast, are caused by blood that has already leaked outside the blood vessels into the skin tissue. Pressing cannot move that blood away, so the spots stay visible. These rashes are described as "non-blanching."
How to do the glass test properly: Take a clear drinking glass (any clear glass will work). Press the side of the glass firmly against the rash. You need to press hard enough that the surrounding skin whitens or pales beneath the glass. Look at the spots through the glass while you are pressing. If the spots disappear, fade, or go pale while the glass is pressed, they are blanching. If the spots stay clearly visible and keep their colour while the glass is pressed against them, they are non-blanching. Do this in a well-lit room. If you are unsure whether the spots are fading or not, treat the rash as non-blanching and act accordingly.
Why non-blanching matters so much
A non-blanching rash can be one of the earliest visible signs of meningococcal disease (meningitis and septicaemia caused by the bacterium Neisseria meningitidis). In meningococcal septicaemia, bacteria in the bloodstream damage the walls of blood vessels throughout the body, causing blood to leak into the skin. The rash often begins as scattered petechiae and can spread and enlarge into larger purple blotches (called purpura) very rapidly, sometimes within minutes to hours.
Meningococcal septicaemia is a medical emergency. It can progress to multi-organ failure and death within hours. Early treatment with intravenous antibiotics is lifesaving, which is why speed of recognition matters so much.
It is important to know that the rash is not always present at the very start of the illness, and a baby with meningococcal disease may have a fever, be difficult to rouse, refuse feeds, or seem unusually floppy and unwell before any spots appear.
What to do if you see petechiae
If your baby has a non-blanching rash and any of the following, call 999 immediately:
- A fever (temperature above 38°C in a baby under 3 months, or above 39°C in an older baby)
- Unusual drowsiness, difficulty waking, or limpness
- A bulging fontanelle (the soft spot on the top of the head)
- A high-pitched or unusual cry
- Sensitivity to light
- Rapid breathing or difficulty breathing
- Pale, mottled, or blue-tinged skin
- Cold hands and feet with a hot body
- The rash is spreading or growing while you watch
Do not wait to see if things improve. Do not call 111 first if your baby is very unwell. Call 999.
If your baby has a non-blanching rash but seems completely well, has no fever, and the rash is not spreading, call 111 or your GP urgently the same day. A non-blanching rash always requires medical assessment, even in a well-seeming child, because early septicaemia can briefly appear before the child's condition deteriorates.
Harmless causes of petechiae
Not all petechiae signal a serious infection. When the pressure inside tiny blood vessels surges suddenly, for example during a prolonged episode of coughing, vomiting, or even very forceful crying, the capillaries can burst, leaving small clusters of petechiae on the face, around the eyes, on the eyelids, or on the neck.
These harmless petechiae have specific characteristics that help distinguish them from the more worrying kind. They typically appear immediately after the triggering episode. They are usually limited to the head, face, and neck. The baby is otherwise well, alert, afebrile, and feeding normally. They do not spread beyond the area where the pressure was concentrated, and they gradually fade over several days as the body reabsorbs the leaked blood.
Even when a harmless cause seems obvious, it is still reasonable to contact your GP or 111 if you are worried, especially if your baby is very young or if you have any doubt.
Other medical causes to be aware of
Beyond meningococcal disease and mechanical pressure, petechiae can occasionally be caused by low platelet counts (thrombocytopenia), certain viral illnesses, or other bleeding disorders. These conditions also need medical evaluation. The key message is the same: any non-blanching rash needs to be seen by a doctor.
How petechiae differ from other spots
Petechiae are flat and cannot be felt by running a finger over the skin. They do not have a raised edge, are not fluid-filled, and do not itch in the way that hives or insect bites do. Their defining characteristic is that they do not blanch. Many other common baby rashes (heat rash, nappy rash, viral rashes, and hives) do blanch under glass. If a rash blanches, it does not guarantee it is harmless, but a non-blanching rash demands faster action.
Frequently asked questions
What does a non-blanching rash look like?
A non-blanching rash stays visible when you press a clear glass firmly against it. The spots do not turn white or fade under pressure. Petechiae look like flat pinprick-sized red, purple, or brown dots. They are not raised, do not feel lumpy to the touch, and can appear individually or in clusters across the skin.
How do I do the glass test correctly?
Press the side of a clear drinking glass firmly against the rash so you can see the skin through the glass. Press hard enough to whiten the skin around the spots. If the spots disappear or fade while the glass is pressed, the rash is blanching and is less likely to be serious. If the spots stay clearly visible and do not change colour, the rash is non-blanching. Do the test in good light. If you are uncertain, treat it as non-blanching and seek help immediately.
Are petechiae always serious?
No. Petechiae can appear after forceful coughing, vomiting, or crying when tiny blood vessels burst from the strain. In this case the spots are usually limited to the face, around the eyes, or on the neck, the baby is otherwise completely well, there is no fever, and the spots do not spread. However, always do the glass test and contact a doctor the same day if you are unsure, because the same appearance can also indicate a serious infection at an early stage.
Can coughing cause petechiae in babies?
Yes. A prolonged coughing episode, a very forceful vomit, or even hard crying can cause enough pressure to burst tiny capillaries under the skin, leaving a cluster of petechiae usually concentrated on the face, eyelids, or neck. These spots typically appear immediately after the event, do not spread beyond the head and neck area, and the baby is otherwise well and afebrile.
Is a petechiae rash the same as a meningitis rash?
Petechiae can be an early feature of the rash seen in meningococcal disease. The rash of meningococcal septicaemia begins as small non-blanching red or purple spots and can spread and enlarge into larger purple blotches very quickly. This is why any non-blanching rash in a baby who has a fever or seems unwell must be treated as a medical emergency and 999 called without delay.
What should I do if I see tiny red spots on my baby?
Do the glass test first. If the spots do not fade under the glass and your baby has a fever, is unusually drowsy, is difficult to wake, or seems very unwell in any way, call 999 immediately and say you think your baby may have meningitis. If the spots do not fade but your baby seems completely well and has no fever, call 111 or your GP urgently for a same-day assessment. Never wait to see if a non-blanching rash improves on its own.
Keep a clear record of your baby's symptoms
When something worries you, having a log of when it started and what you observed makes it easier to describe to a doctor quickly.
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