Petechiae: Causes, Symptoms and Treatment

Petechiae are red, purple or brown spots smaller than 2mm. They do not disappear when you put pressure on them and usually appear on your legs, buttocks, stomach or arms. When they are larger than 2mm, they are called purpura.

Petechiae are caused by bleeding under the skin. While petechiae can be quite common, you should still see a doctor about it to make sure it isn’t being caused by a serious underlying health condition.

If you care for a child who develops extensive and unexplained petechiae, seek immediate medical advice.

Petechiae can look different depending on where you get them on your body. Here are some of the signs to look for in petechiae spots:

• do not change colour when you put pressure on them (called non-blanching)
• red, purple or brown
• less than 2mm
• round in shape, like a pinpoint
• lie flat against your skin
• appears in clusters

Petechiae are not normally painful or itchy.

How long petechiae last and whether there are long-lasting complications from them depends on what’s caused them in the first place.

You can tell if spots are non-blanching (their appearance doesn’t change under pressure) by using the glass test. This is where you press a glass against the spots to see if they disappear. If they do not disappear, they are non-blanching.

When should I talk to a doctor about my petechiae?

Talk to your doctor about your petechiae if they are widespread and you do not know why they have appeared. Petechiae can indicate an underlying health condition which may need immediate treatment.

Get urgent medical attention if you have petechiae and you also:

• have a fever
• feel very unwell and are getting worse
• notice the spots are spreading or getting bigger
• see other bruising on your body
• experience changes in your heart rate or pulse
• have trouble breathing
• experience a shift in consciousness or confusion

If you are looking after a child who develops petechiae, seek urgent medical attention.

You get petechiae when tiny blood vessels called capillaries leak blood into the skin.

There are three main reasons that the blood vessels can leak:

1. Physical straining in the body

Petechiae can appear when your body severely strains itself during the following:

• vomiting
• coughing
• childbirth
• weight-lifting
• injury

2. Reaction to medications

It is possible to get petechiae as a side effect of taking medication, including sedatives, anti-seizure drugs, antibiotics, antidepressants, blood thinners, heart-rhythm drugs and nonsteroidal anti-inflammatories.

Examples of these medications include:

• phenytoin
• quinine
• penicillin
• aspirin
• lidocaine/prilocaine cream
• furosemide
• warfarin
• carbamazepine
• desipramine
• atropine

3. Medical conditions

Various medical conditions can cause petechiae.

• Reactions to insect bites or infections caused by insects, such as Rocky Mountain Spotted Fever
• Viral infections such as Dengue fever, enterovirus and parvovirus B19
• Bacterial infections such as meningitis
• Sepsis
• Autoimmune diseases
• Cancer, such as leukaemia
• Vitamin K deficiency
• Scurvy
• Thrombocytopenia (where your blood platelets decrease)
• Henoch-Schölein purpura (where your blood vessels become inflamed)
• Vasculitis (where blood vessels become inflamed)

Having petechiae does not automatically mean you have one of these conditions. These conditions usually occur with several other symptoms. It is essential to tell your doctor about all your symptoms so that they can work out the underlying condition and start your treatment as soon as possible.

What increases my risk of getting petechiae?

As petechiae can appear as a result of many different causes, there are no specific risk factors that increase your chance of getting it.

A doctor can diagnose petechiae by examining the non-blanching, pinpoint spots. To determine what is causing them, the doctor may ask you questions about your health, conduct a physical examination and order specific tests.

How a doctor treats petechiae will depend on what has caused them.

Physical straining: the treatment will involve resting, drinking lots of fluids and possibly taking medication (e.g. to stop you from being sick or coughing).

Reaction to a drug: the treatment may involve waiting until the end of the course or finding an alternative medication.

Specific medical condition: doctors will prescribe treatments to help with that condition. These can include:

• antibiotics to treat an infection
• medications for overactive immune systems
• cancer treatments such as chemotherapy and radiation
• drugs to reduce inflammation

As so many factors can cause petechiae, it is impossible to prevent all potential underlying causes. Keeping fit and healthy through regular exercise, a balanced diet, drinking plenty of water and getting enough sleep can help to reduce your chances of developing a severe medical condition.If certain medications cause you to get petechiae, you can avoid taking them where possible.As infections can cause petechiae, taking the following precautions can reduce your risk of getting an infection:

• careful and regular hand washing
• practise safe sex
• avoid those who are ill
• avoid sharing utensils and glasses with others
• use insect-repellent and take precautions to prevent ticks 

Purpura is a similar condition to petechiae. The difference is that the spots are bigger than 2mm if you have purpura.

Cherry angioma has similar-looking spots to petechiae, but some key differences exist. They are usually deep red or cherry pink, can be larger than petechiae and appear in isolation rather than clusters. Cherry angioma is a small benign growth on the skin rather than bleeding in the skin.