Petechiae vs. Purpura: What Skin Discoloration Can Tell You About Your Health

A variety of discolorations can appear on the skin for a wide range of reasons. There are two types of skin discolorations that may be seen that are associated with bleeding under the skin. These may appear in groups or be clustered together and may look like a rash.

Petechiae are pinpoint spots on the skin, often red in color, and purpura are larger areas that may be more purple in color.

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Both of these are flat discolorations on the skin.

This article will review petechiae and purpura—what they look like, potential causes, and how they are treated.  

Petechiae vs. Purpura: Difference in Appearance

The main difference in appearance between petechiae and purpura is their size:

• Petechiae are very small, less than 4 millimeters (mm) in size.
• Purpura are larger areas of bleeding under the skin, typically between 4 mm and 10 mm.

Areas that are larger than 10 mm are referred to as ecchymosis, also known as bruising.

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Causes

Petechiae and purpura can develop for many reasons, all with the underlying cause of bleeding from a broken blood vessel. Some of the causes of these skin discolorations include:

• Trauma
• Medications
• Other medical conditions

These can occur on any area of the skin, including the inside of the mouth.

Trauma or Injury

If a person sustains some type of injury or accident, this trauma can cause direct damage to a blood vessel. This trauma then causes blood to leak out into the skin.

Sometimes straining, experienced in situations such as childbirth or with vomiting, may cause petechiae or purpura to form.

Medication

Certain medications may make petechiae or purpura develop. These medications are often associated with preventing platelets from sticking together, which is usually important when there is concern about the development of blood clots.

These medications may include:

• Aspirin
• Clopidogrel (Plavix)
• Warfarin (Coumadin)
• Steroids
• Some chemotherapy medications

Medical Conditions or Infections 

Multiple medical conditions may lead to the development of petechiae or purpura. These disorders may cause damage to the blood vessels or have other complications associated with them that make bleeding more likely.

These conditions are typically due to:

• Autoimmune disorders
• Leukemia (blood cancer)
• Other cancers
• Low platelet counts (thrombocytopenia)
• Fragile blood vessels associated with aging
• Inflammation of the blood vessels
• Thrombotic thrombocytopenic purpura (TTP)
• Immune thrombocytopenia (ITP)

Different infections can also cause bleeding under the skin. Some of these infections include:

• Sepsis infection in the blood or other tissues in the body
• Cytomegalovirus infection

Treatment

Petechiae and purpura are treated by providing treatment for the underlying condition that is causing them to develop. 

If the cause of the bleeding is trauma, sometimes all that is needed is time to allow those blood vessels to heal. 

If they are caused by severely low platelet counts, a platelet transfusion may be needed to stop the bleeding. 

If petechiae or purpura are caused by medications, withholding the medication may be necessary to prevent any further bleeding. 

When to Call a Healthcare Provider

Seeking evaluation when petechiae or purpura develop is important so that the underlying cause of these can be evaluated. It is especially important to seek out medical care if any other symptoms, such as fever or severe fatigue, are also present, or if other, more severe bleeding is occurring.

Frequently Asked Questions

How long does it take for purpura or petechiae to fade?

It can take a few weeks for the purpura or petechiae to fade as the blood is reabsorbed by the tissue. 

When should petechiae make me worry?

When petechiae occurs spontaneously for an unknown reason, or is associated with other symptoms such as fever, fatigue, or other bleeding, seeking medical care is appropriate.

Are there home remedies to treat purpura and petechiae? 

There are no specific home remedies to treat purpura or petechiae. Protecting the skin against trauma or accident can help to prevent these from occurring. If either of these conditions develop, notify your healthcare provider.

How are purpura and petechiae diagnosed?

Purpura and petechiae are diagnosed through a physical examination of the skin to evaluate for the presence of the flat red- or purple-colored areas. A health history and review of medications can be important to help determine the reason why purpura or petechiae developed.