Petechiae: thrombosis signal after vaccination?

Petechiae are bleeds in the skin that appear as small red dots and are often mistaken for a rash or other skin condition. Bleeding of the skin can have various causes. A blood clotting disorder resulting from a coronavirus vaccination with Vaxzevria®, AstraZeneca’s COVID-19 vaccine, can be behind it. The rare side effect can result in a dangerous sinus vein thrombosis. Therefore, the Standing Vaccination Commission (STIKO) advises paying particular attention to the body’s warning signals after the vaccination to react in good time. Please find out how to recognize petechiae, why they can be a significant warning signal for thrombosis and which other causes are possible. 

Recognizing petechiae: Here’s how

What does the bleeding in the skin look like? The pinhead-sized dots usually occur in clusters and are reminiscent of a small bruise, as they neither itch nor cause pain. The punctate skin haemorrhages initially appear reddish-violet, later brownish. They can affect the skin or mucous membranes – they often appear on the arms or legs, the stomach or buttocks or, for example, in the mouth or the eyelids.

To distinguish petechiae from a skin condition or rash, Use a spatula or clear drinking glass to apply pressure to the affected area of ​​the skin. A rash will disappear with the pressure, while petechiae will still be easy to see.

With petechiae, the blood cannot be pushed away because it leaks out of the capillaries and collects in the skin. In the case of a rash, on the other hand, the blood is still in the vessel, and the reddening disappears when you press it.

 

Are Petechiae Normal?

Petechiae are not a disease in their own right but a symptom. Therefore, it is always essential to determine the cause of capillary bleeding. This is often harmless, and the petechiae will disappear independently after a few days.

These harmless causes include, for example, mechanical trauma caused by pressure on the skin or friction – for example, from scratching, the rubbing of a heavy piece of luggage or tight shoes. In rare cases, severe coughing or vomiting, childbirth, or a head injury can also trigger petechiae.

Petechiae can also occur as a side effect of medication, for example, with certain blood thinners, painkillers, antiepileptic drugs or antibiotics.

Petechiae can also be a warning sign of a severe illness. Possible triggers are diseases such as pneumococcal or meningococcal infection, tonsillitis, cytomegalovirus disease, amyloidosis, and scarlet or glandular fever. Likewise, vascular injuries or inflammations such as vasculitis or its subtype Henoch-Schönlein purpura and Ehlers-Danlos syndrome can cause skin bleeding. Petechiae can be one of the first signs of leukaemia.

A doctor should clarify the cause of the petechiae. This is especially true when additional symptoms appear.

Petechiae: warning sign of a blood clotting disorder

Petechiae often develop in connection with a blood clotting disorder. A lack of blood platelets (thrombocytes) can lead to punctiform bleeding since the smallest blood vessels can no longer be sealed sufficiently. Minor bleeding occurs in the surrounding skin areas.

A consequence of the blood platelet deficiency (thrombocytopenia) is an increased tendency to bleed, which manifests itself in the following symptoms:

• Hematoma after small bumps
• nosebleeds
• bleeding gums
• persistent menstrual bleeding

Such a lack of blood platelets can have many different reasons. These range from anaemia (low blood count) due to a vitamin or iron deficiency to damage to the bone marrow from leukaemia or other diseases.

 

Heparin-induced thrombocytopenia (HIT)

Platelet deficiency can also occur in connection with the anticoagulant heparin. This is mainly used as a thrombosis prophylaxis after injuries and operations. In rare cases, however, this leads to thrombocytopenia.

After administration of the heparin, the number of thrombocytes decreases a little; after a few days, the thrombocyte count returns to normal on its own, and the treatment can be continued. This is referred to as type 1 heparin-induced thrombocytopenia.

Type 2 HIT is significantly more dangerous: The heparin leads to an autoimmune reaction: Antibodies are formed, activating the platelets and promoting clot formation, increasing the risk of thrombosis and circulatory disorders. Depending on the vessel and severity, this can have life-threatening consequences.

COVID-19 vaccination: thrombocytopenia possible

After examining blood samples on the connection between sinus vein thrombosis (thrombosis of the cerebral veins) after the AstraZeneca vaccination, researchers assume that the coronavirus vaccination can also trigger thrombocytopenia. Similar to heparin-induced thrombocytopenia type 2, this can lead to an autoimmune reaction and have serious consequences such as pulmonary embolism and sinus vein thrombosis.

Vaccinated people should, therefore, be on the lookout for any symptoms four to 16 days after the vaccination and seek medical advice in case of problems or abnormalities. After checking the platelet count, treatment can be initiated. The therapy for petechiae always depends on the respective cause.