Serious toxin complications widely under–reported, suggests evidence review
One in six botulinum-toxin patients suffer side effects or more serious complications, says a new study, with cases likely vastly under-reported.
Research findings from a review of global evidence undertaken by four doctors and academic researchers – three of whom are plastic surgeons – at the Royal Free and St Thomas’ hospitals in London, show a 16% complication rate with toxin injections, according to The Observer, with which the findings were exclusively shared.
Side effects including bruising, headaches, nausea and “frozen” facial features were most widely reported in the evidence reviewed by the researchers, with more severe complications such as muscle stiffness, pain, dizziness and heart attack also apparent.
The team analysed 30 studies involving 17,352 injections of botulinum toxin into the face. Localised skin reactions or bruising (5%), headache (3%) and facial paralysis (2%) were found to be the most common adverse reactions.
While medical aesthetic professionals are well aware of the possible side effects and complications of toxin treatment, the report’s authors were mostly concerned with the disparity between the high number of incidents that occurred and that which were actually reported to the MHRA (Medicines and Healthcare products Regulatory Agency). The researchers found that only 188 “adverse reactions” were reported.
Lead author of the study Dr David Zargaran told The Observer: “I was surprised to find such a low number of incidents reported to the MHRA. It was surprising as it equates to less than 10 adverse events a year across the UK. I believe the MHRA database of complications is a significant underestimate of the total number of complications.”
Of the adverse reaction reports submitted to the MHRA between 1991 and 2020, the 188 patients had experienced a total of 481 side effects between them, suggesting that frequently, more than one side effect is experienced at the same time. In 28% of the MHRA reports the patient had flu-like symptoms or a chill, while in 27% they had a headache or migraine.
25 reports – one in eight – recorded cardiovascular symptoms ranging from high blood pressure to an abnormally fast heart rate and heart attacks. Small numbers also suffered an anaphylactic reaction or wound infection such as cellulitis. These exact numbers are as yet unreported.