Difference Between Petechiae and Purpura (With Table)

Skin problems are something that almost every individual faces in one way or another. They can be caused due to various reasons such as health conditions, stress, hormonal imbalances, and so on. However, there are some, if not diagnosed, that can lead to further damage, like Petechiae and Purpura.

Petechiae vs Purpura

The main difference between petechiae and purpura is that Petechiae is somewhat a smaller version of Purpura. Purpura and petechiae refer to the skin discoloration or red spots that appear on the skin. There are many similarities between the two but also some differences in etymology, appearance, size, cause, and meaning.

Petechiae is a condition in which there is discoloration of the skin. In this situation, small patches of different colors occur. They are mainly red, pink or purple. These patches occur within the layer of the skin. Due to the breakage of the blood vessels present under the skin, which causes bleeding.

Purpura is another condition in which there is skin discoloration. It is similar to the situation of small patches of mainly red, pink, or purple colors. Also caused due to the breakage of the blood vessels present under the skin, which causes bleeding. However, they are bigger in size.

Comparison Table Between Petechiae and Purpura

Parameters of Comparison

Petechiae 

Purpura

Etymology

The term is derived from the modern Latin and Italian words ‘petecchia’ as well as the Latin word ‘petigo.’

The term is derived from the Greek word ‘porphura,’ meaning  ‘purple.’

Appearance

These are different colored patches, mainly red, pink, or purple, below the skin, which are predominantly flat. 

These are different colored patches, also mainly red, pink, or purple, within the skin which can be flat or raised.  

Size

Their usual size is less than two millimeters.

Their usual size is more than two millimeters.

Cause

Due to the leaking of the capillaries caused by breakage under the skin. They may also be formed around purpura or among them.

They are caused by the breakage and leakage of blood capillaries under the skin.

Meaning

They are also known as smaller purpuras.

They are a symptom of a medical condition.

What is Petechiae?

This term is a formation of the words ‘petecchia’ and ‘petigo,’ which mean ‘a freckle or spot on the face’ and ‘scab, eruption.’ They are also known as ‘Blood Spots.’ The reason behind this is also the same. Sometimes the small capillaries of blood present under the skin burst, and the blood in these capillaries leaks. The leakage of blood leads to the formation of patches under the skin. These patches appear in different colors, mainly red, pink, or purple. Petechiae are one of the patches that occur due to this situation. The size of these patches, in this case, is smaller than two millimeters. Also, they are flat in general.

The leaked blood is then absorbed by the body. And in this process, the color of these patches also changes. The transition is as follows: pink-red-purple- brown/ orange/ blue/ green. The fading of these spots does not occur under pressure. They seem like some kind of a rash. These can spread to the regions of the skin surrounding that area. They also occur in the case of Purpura, around them or among them. These can develop in the case of children, too, and are a symptom of a medical condition and can be treated in many ways. They are somewhat smaller versions of purpura.

What is Purpura?

Purpura is the bigger version of petechiae. Purpura is another situation that occurs due to the blood leak from capillaries. There are various reasons due to which the blood capillaries burst and cause leakage of blood. These are also usually in red, pink, or purple colors. However, the size, in this case, is more than two millimeters and, in some cases, is slightly raised.

They can also occur under mucous membranes. Purpuras also seem like blood clusters and rashes. And also change color with the absorption of leaked blood by the body. The affected areas define the amount of leakage of underlying blood. Purpuras are larger than petechiae.

They are, however, not irritating or itchy. These, too, are a symptom of a medical condition that may be more severe. But in most cases, they are treated even with simple steps. There are mainly 3 types of purpura and petechiae: Thrombocytopenic purpura and petechiae, Non-thrombocytopenic purpura and petechiae, and Purpura and petechiae from other clotting disorders. There are different conditions that lead to the formation of purpura and petechiae: UV light damage, aging of the skin, collagen loss, various vitamin deficiencies, allergic reactions, medications, surgeries, skin damage, or blood vessel damage. 

Main Differences Between Petechiae and Purpura

  1. The term petechiae are derived from the modern Latin and Italian words ‘petecchia’ and the Latin word ‘petigo’. The term purpura is derived from the Greek word ‘porphura,’ which means ‘purple’.
  2. Petechiae are those different colored patches mainly red, pink, or purple below the skin which are predominantly flat. Purpura is the different colored patches, also mainly red, pink, or purple within the skin, which can be flat or raised.  
  3. The usual size is less than two millimeters in the case of petechiae. The usual size is more than two millimeters in the case of purpura.
  4. The leaking of the capillaries caused by breakage under the skin cause petechiae. However, it may also be formed around purpura or among them. Purpura is a result of the breakage and leakage of blood capillaries under the skin.
  5. Petechiae are also known as smaller purpuras. Purpura is a symptom of a medical condition.

Conclusion

Both Purpura and petechiae refer to the red, pink, or purple spots on the face that seem to be a rash. However, they are a result of breakage and leakage from blood capillaries. Purpuras are larger in appearance than petechiae. They have different types and causes. They are both symptoms of a medical condition and therefore should be diagnosed by a doctor to reduce further damage.

Especially in the case of children when they also have a fever. Contacting the doctor is also necessary for others with additional symptoms. Both the conditions need treatment. If not diagnosed properly can lead to serious complications.

References

  1. https://www.researchgate.net/profile/Marjolein-Wintzen/publication/8588806_Autoimmune_progesterone_dermatitis_presenting_with_purpura_and_petechiae/links/59e4541eaca2724cbfe76067/Autoimmune-progesterone-dermatitis-presenting-with-purpura-and-petechiae.pdf
  2. https://www.bmj.com/content/352/bmj.i1285.abstract