Petechiae or purpura: symptoms, causes & treatment

Petechiae are tiny, flat hemorrhages in the skin with a diameter of less than 2 millimeters. They appear as dotted red, burgundy, or purple spots that do not blanch when pressed with a glass. Purpura is the umbrella term for skin hemorrhages larger than 2 millimeters but smaller than 1 centimeter. Ecchymosis (bruises) are similar but larger than 10 millimeters.

The distinction can be made with the glass test (diascopy): press a clear glass firmly onto the spots. If the color does not disappear, it is almost certainly due to hemorrhages in the skin. Ordinary skin redness due to inflammation or allergy will blanch when pressed.

Several subtypes exist within purpura. Henoch-Schönlein purpura (HSP) is an autoimmune reaction where blood vessels show inflammation; the purpura typically appears on the legs and buttocks in children. Idiopathic thrombocytopenic purpura (ITP) occurs when the immune system attacks platelets, leading to insufficient blood clotting. Senile purpura (also known as Bateman's purpura) is the harmless variant in older adults: due to aged connective tissue around small blood vessels, minor bleeding easily occurs, often on the arms and hands.

Petechiae and purpura occur when small blood vessels (capillaries) rupture or leak, causing blood to seep into the surrounding skin. The causes range from completely harmless to medically urgent.

Increased mechanical pressure from severe coughing, vomiting, or straining causes increased pressure in the head and neck area, which can lead to small blood vessels around the eyes and on the face rupturing. This is harmless and resolves on its own.

Heat and sun exposure can temporarily increase the fragility of capillaries in sensitive individuals. Aging weakens the connective tissue around small blood vessels, leading to purpura from minor bumps or even spontaneously.

Certain medications increase the risk: blood thinners reduce clotting ability, corticosteroids make the skin thinner and more fragile. Vitamin C is essential for collagen production around blood vessels; a deficiency leads to brittle capillaries. Vitamin K is necessary for blood clotting; a deficiency increases the likelihood of small hemorrhages. More about itching as an accompanying symptom in skin conditions can be found on the Skindr page about itching.

Viral infections (including enteroviruses, EBV, and influenza) can cause petechiae in children due to direct capillary damage or thrombocytopenia. Clotting disorders such as thrombocytopenia (too few platelets) prevent small hemorrhages from stopping quickly. Autoimmune diseases and vasculitis cause inflammation in the vessel wall itself, leading to purpura.

In bacterial infections such as meningococcal sepsis, bacteria actively damage the walls of small blood vessels. The petechiae here spread extremely rapidly and constitute a medical emergency.

Petechiae are flat, non-raised, and do not itch. On light skin, they appear as bright red or burgundy spots. On dark skin, they are dark brown or purple and less visibly contrasting. Good lighting and the glass test are the most reliable ways to identify them on any skin tone.

With purpura, the spots are larger, sometimes coalesce, and can be red-purple to brownish-red in color. If vasculitis is the cause, the spots may be slightly palpable (palpable purpura).

Red flags: when is it an emergency?

Fever combined with petechiae in a child is a medical emergency until proven otherwise. Call 112 if: fever and petechiae in a child, a rapidly spreading rash (within hours), neck stiffness, confusion, or a child who is abnormally drowsy. You can read more about skin complaints at a young age on the page about skin problems in children.

Other red flags: petechiae that coalesce into large purpura patches, unexplained bleeding elsewhere in the body, and petechiae in a newborn.

"Petechiae and leukemia" is a frequently searched combination. Leukemia-related petechiae are rare and always accompanied by other symptoms such as extreme fatigue, paleness, and unintentional weight loss. Isolated petechiae without other symptoms are rarely a sign of skin cancer, but always have any doubts assessed by a doctor. Also read about melanoma if you are concerned about dark skin lesions.

If your symptoms are not urgent but you still want reassurance? A certified Skindr dermatologist will assess your skin lesion within 48 hours.

The location provides a clue about the possible cause. Petechiae after coughing or straining typically appear around the eyes, on the forehead, and neck. Senile purpura is almost exclusively limited to the back of the hands and forearms, where the skin is thinnest. HSP purpura appears symmetrically on the extensor surfaces of children's legs and buttocks.

In viral infections, petechiae are scattered over the trunk and limbs. In ITP and other thrombocytopenias, they can occur throughout the body, including the oral mucosa and the whites of the eyes.

Petechiae most commonly occur on the legs and ankles at all ages, because capillary blood pressure is highest in the lower parts of the body and small vessels there are the first to rupture with increased pressure or vasculitis.

Treatment depends entirely on the underlying cause. Petechiae after coughing or straining are harmless and resolve spontaneously within one to two weeks without any intervention.

For vitamin C or K deficiency, correction through diet or supplementation is the approach. The petechiae quickly diminish once the vitamin status improves. If medication is the cause (blood thinners, corticosteroids), the doctor will discuss whether adjustment is possible and safe.

If infection is the cause, treating the infection is paramount. For meningococcal sepsis or other bacteremias, immediate hospitalization is necessary.

ITP and other autoimmune forms of thrombocytopenia are treated by a hematologist. Depending on the severity, treatment can range from watchful waiting to corticosteroids, immunosuppressants, or other targeted approaches. For HSP in children, the prognosis is good, but kidney involvement requires follow-up by a pediatrician or nephrologist.

A dermatologist assesses the skin, determines the cause, and refers to a general practitioner, hematologist, pediatrician, or internist as needed. If you have doubts about a skin biopsy as a next step, you can read all about it on the page about skin biopsy. Skindr offers an accessible entry point for this: no referral letter, no waiting list.

Through Skindr, you receive advice from a certified dermatologist within 48 hours.

Hydrocortisone cream and antihistamines have no effect whatsoever: petechiae and purpura are not allergic reactions but small hemorrhages in the skin. Antihistamines can help with hives, which may visually resemble purpura but has a different cause.

Massaging or rubbing the spots is also ineffective: the blood outside the vessels can only be broken down by the body itself, which takes one to two weeks.

Warm or cold compresses do not alter the rate at which petechiae disappear.

Stopping blood thinners or other medications on your own if you suspect a side effect is dangerous: never do this without consulting a doctor.

In cases of red flags (fever, rapidly spreading rash in a child), waiting or self-treatment can be life-threatening. Call 112 or go to the emergency department immediately.

What is the difference between petechiae and purpura?‍

Petechiae are spots smaller than 2 mm; purpura are larger spots ranging from 2 to 10 mm. Neither disappears with the glass test. Ecchymoses (bruises) are larger than 10 mm.

Are petechiae a sign of leukemia?‍

Rarely. Most petechiae are harmless. Leukemia-related petechiae are always accompanied by other symptoms: extreme fatigue, paleness, weight loss. If in doubt, consult a dermatologist.

Which vitamin deficiency causes petechiae?‍

Deficiency of vitamin C (needed for collagen around blood vessels) or vitamin K (needed for blood clotting). Both deficiencies increase susceptibility to small hemorrhages.

Do petechiae disappear on their own?‍

When caused by mechanical pressure, they disappear within one to two weeks. Purpura caused by an underlying condition will only disappear once that cause is addressed.

How do I perform the glass test?‍

Press a clear glass firmly onto the spot. If the spot fades: normal skin redness. If the spot remains visible: likely petechiae or purpura.

Are petechiae dangerous in children?‍

Yes, if accompanied by fever: it could be meningococcal infection or sepsis. If a child has fever and petechiae, go to the emergency room immediately or call 112.

When should I see a dermatologist?‍

For petechiae without a clear cause, recurring spots, or if you are unsure. Through Skindr, you will receive an assessment within 48 hours, without a referral.

Can Skindr help with petechiae or purpura?‍

Yes, for non-urgent cases. Send a photo via Skindr and receive advice from a certified dermatologist within 48 hours. For red flags (e.g., fever in a child): go to the emergency room immediately.

1. Skindr (www.skindr.com)
2. DermNet NZ: Purpura and Petechiae | dermnetnz.org
3. Gezondheid.be: Red spots on the skin (2024)
4. GezondheidEnWetenschap.be: Henoch-Schönlein Purpura — Belgian EBM guideline
5. MSD Manual: Purpura and Petechiae — clinical reference