Petechiae are pinpoint red spots that are less than 2 mm and usually flat, while purpura are bigger, ranging from 2 mm to 1 cm in size, and may be palpable in some cases.
Ecchymoses are the largest of all and are more than 1 cm. In addition, petechiae are usually round while purpura and ecchymoses can be irregular in shape.
Overview
Petechiae, purpura, and ecchymosis are areas of skin discoloration that appear due to bleeding into the skin. The discolored areas may be red, reddish brown, or purple.
Petechiae are smaller areas of skin discoloration while purpura and ecchymosis are bigger in size. In some cases, one can see these skin lesions together.
Petechiae can appear in clusters like a rash, but these occur due to broken or leaky blood vessels. If you press on them, these do not fade unlike other rashes.
In addition, petechiae and purpura are not itchy, which may help in differentiating them from other skin conditions.
This article reviews the differences between petechiae, purpura, and ecchymosis, their causes, and treatment options.
Difference in appearance
The main difference between petechiae, purpura, and ecchymosis is their appearance.
Petechiae are small blood spots that are less than 2 mm in size. They usually appear as round flat pinpoint red spots on the skin.
Purpura are larger blood spots and are more than 2 mm in size, but less than 1 cm. The shape may depend on the area involved. Some purpura, especially those due to vasculitis (inflammation of blood vessels) can be raised.
Bleeding spots that are larger than 1 cm are referred to as ecchymosis.
Most of the time, petechiae appear due to platelet disorders like thrombocytopenia while ecchymosis or larger bleeding spots appear due to coagulation disorders like hemophilia.
Causes
Petechiae, purpura, or ecchymosis can appear due to various reasons. These may involve platelets, clotting factors, or blood vessels.
- Platelets are a type of blood cells that are required for normal clotting of blood.
- Clotting factors are proteins in our blood that help in normal blood clotting.
- Blood vessels carry blood in our bodies.
Some of the common causes include:
1. Thrombocytopenia
Thrombocytopenia is the decrease in the number of platelets in our body. This decrease can be due to: increased destruction of platelets, a decrease in their formation, or due to dilution (like massive blood transfusion).
Increased destruction can occur in certain infections, enlarged spleen, autoimmune disorders, drugs, bleeding disorders like hemolytic uremic syndrome (HUS), and disseminated intravascular coagulopathy (DIC).
Decreased formation of platelets can occur due to suppression of the bone marrow due to drugs, infections, or blood cancer like leukemias.
2. Medications
Medications can cause ecchymosis, purpura, or petechiae in several ways. They can activate the immune system which destroys the platelets or they can affect the platelet’s function (they can prevent clumping of platelets which helps to stop the bleeding).
Drugs that are commonly associated with bleeding spots are:
- NSAIDs like aspirin
- Heparin
- Warfarin
- Antibiotics like penicillin, sulfonamides
- Quinine
- Anti-seizure medications
- Steroids
- Chemotherapy drugs
- Certain heart medications.
3. Disorders of vessels
Blood vessels carry blood and if the vessels are damaged by trauma or they become fragile, it can lead to petechiae, purpura, or ecchymosis.
This can occur due to:
- Vasculitis: This is the inflammation of the blood vessels. It is of various types and the symptoms may vary depending on the type. (Example: Henoch-Schonlein purpura – HSP)
- Aging: With aging, the blood vessels may become weak and more prone to damage with minimal trauma.
- Connective tissue disorders: This includes disorders that may affect the wall of the vessels making them fragile (example: Ehlers-Danlos syndrome).
4. Vitamin deficiencies
Petechiae, purpura, or ecchymosis can appear due to two vitamin deficiencies – vitamin C deficiency and vitamin K deficiency.
- Vitamin C deficiency can lead to scurvy and weak or fragile blood vessels.
- Vitamin K is required for the production of some of the proteins required for the normal clotting of blood. So, its deficiency may lead to petechiae.
5. Infections
Infections can lead to petechiae, ecchymosis, or purpura in different ways: they can abnormally activate the coagulation pathway consuming the platelets, can damage the blood vessels, or can destroy platelets via activation of the immune system.
- Viral infections include Parvovirus B19, cytomegalovirus (CMV), infectious mononucleosis due to Epstein-Barr virus (EBV), viral hemorrhagic fevers such as Lassa fever, dengue, Ebola, and yellow fever.
- Bacterial infections include meningococcemia due to Neisseria meningitidis, Rocky Mountain spotted fever, scarlet fever, and infective endocarditis.
- Fungal infections like candida.
6. Other causes
In addition, there are several other causes that can affect the blood vessels, platelets, or coagulation pathway which can lead to bleeding spots.
- Trauma
- Straining
- Seizures
- Congenital disorders which can affect platelet function like Bernard Soulier disease and Glanzmann thrombasthenia.
- Uremia.
- Chronic liver disease.
- Pregnancy
Treatment
The treatment for these bleeding spots depends on their underlying cause. If they are due to weight lifting or bouts of coughing, they may disappear on their own. Remedies such as applying a cold compress, increasing fluid intake, and getting rest may help.
If they appeared due to medication, your doctor may change the dose, stop the medication or prescribe another medication.
The other treatment options include:
- Dietary modification or supplementation if it’s due to vitamin C or K deficiency.
- Antibiotics to treat infections.
- Antivirals.
- Steroids.
- Removal of spleen if it’s enlarged.
- Medications that stimulate the bone marrow to form platelets.
- Bone marrow transplant.
- Platelet transfusion.
When to see a doctor
Any skin lesion that appears for an unknown reason should be examined by a doctor. So, if you develop these bleeding spots, it is recommended that you see a doctor to identify the underlying cause, as they could be a sign of a serious condition.
In addition, one should see a doctor immediately if:
- The petechiae, purpura, or ecchymosis are spreading quickly on the body.
- They are accompanied by fever, fatigue, or night sweats.
- You do not feel well.
- There is bleeding from the nose or mouth or you see blood in urine and stools.
- You are dizzy or confused.
Note: Any child with fever and petechiae or purpura, requires immediate medical attention.
FAQs
How long do petechiae last?
Petechiae may last for a few days to weeks if they occur due to non-serious causes like trauma or coughing. However, if the petechiae are due to other more serious conditions, their persistence will depend on the cause and whether the underlying skin condition is treated.
Telangiectasia vs petechiae: What is the difference?
Telangiectasias are dilated blood vessels that will blanch when pressure is applied, while petechiae are bleeding spots that do not fade or blanch with pressure.
Key points
Petechiae, purpura, and ecchymosis appear due to bleeding into the skin. The main difference between them is size. Petechiae are flat red or purple spots less than 2 mm in size. Purpura are bigger in size, between 2 mm to 1 cm, while ecchymoses are more than 1 cm.
They can occur due to various reasons, ranging from harmless like minor injury to serious conditions like systemic or widespread infections or leukemia.
Petechiae, purpura, or ecchymosis are not a medical condition but a sign of other medical conditions. So, they should be evaluated by a doctor to find the underlying cause.
References
- Pietras NM, Pearson-Shaver AL. Immune Thrombocytopenic Purpura. [Updated 2022 Nov 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
- McGrath A, Barrett MJ. Petechiae. 2022 Sep 12. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 29493956.
- Downes AJ, Crossland DS, Mellon AF. Prevalence and distribution of petechiae in well babies. Arch Dis Child. 2002 Apr;86(4):291-2. doi: 10.1136/adc.86.4.291. PMID: 11919110; PMCID: PMC1719144.
Disclaimer: This blog post is for information purposes only and does not replace medical advice.