NICE has (on 29 July 2021) published a new rapid COVID-19 guideline to help healthcare staff identify and treat patients who develop the rare syndrome vaccine-induced immune thrombocytopenia and thrombosis (VITT) after receiving COVID-19 vaccinations.
Rare: only 14.2 cases occurring per million doses of COVID-19 vaccine
New or ongoing symptoms within 5 to 30 days of having had a COVID-19 vaccination.
Signs and symptoms
• new onset of severe headache, which is getting worse and does not respond to simple painkillers
• an unusual headache which seems worse when lying down or bending over, or may be accompanied by blurred vision, nausea and vomiting, difficulty with speech, weakness, drowsiness or seizures
• new unexplained pinprick bruising or bleeding
• shortness of breath, chest pain, leg swelling or persistent abdominal pain.
Unwell: refer to A&E immediately
Not acutely unwell (and results can be obtained and reviewed on the same day): Do a FBC asap.
- If low plts then refer to A&E same day
- Normal FBC - safety net
High clinical suspicion of VITT remain: Repeat FBC in 2-3/7 if symptoms worsen, or d/w haematologist.
Confirmation of Dx: ELISA (enzyme-linked immunosorbent assay), that detects a certain antibody that people with VITT have called platelet factor 4 (PF4). However, if healthcare staff suspect that a patient has VITT they should start treatment in consultation with a haematologist without waiting for ELISA results.
If the person has developed thrombosis, healthcare staff should perform same-day imaging tests such as a CT scan to confirm where the blood clot is before starting treatment.