Iatrogenic botulism following botulinum toxin injection: a scoping review of clinical characteristics, risk factors, and dermal considerations.

Study purpose: Botulinum toxin (BoNT) is commonly used for both cosmetic and medical purposes. However, improper use can lead to iatrogenic botulism. This scoping review aimed to evaluate the systemic and skin-related effects, identify risk factors, and highlight safety gaps in BoNT-related botulism.

Methods: We followed PRISMA-ScR guidelines to search for literature from 1997 to 2024 across PubMed, Scopus, EMBASE, and Google Scholar. Ten case reports (113 patient cases) met the inclusion criteria.

Results: Females accounted for 78.8% of cases. Systemic symptoms typically developed within four days after the injection. Notably, 46% of cases involved unlicensed BoNT products, raising safety concerns. Among the licensed formulations, Abobotulinum toxin A accounted for 33.6% of cases, Onabotulinum toxin A for 10.6%, and other or unspecified products for 9.7%. Doses ranged from 100 to 2000 units (average of 487±312 units). Intramuscular injection was the most common method at 60.2%. Common symptoms included dysphagia in 82.3% of cases, ptosis in 78.8%, and generalized weakness in 65.5%. Respiratory failure occurred in 12.4% of severe cases. Interestingly, there were no consistent reports of skin or injection-site reactions, suggesting potential underreporting of skin-related effects. Treatments included antitoxin in 59.3% of cases and pyridostigmine in 24.8%. The majority of patients, 86.7%, fully recovered, though six experienced symptoms lasting over six months.

Conclusion: Both licensed and unlicensed BoNT products can lead to iatrogenic botulism. Inconsistent reporting of skin complications highlights a gap in safety data. Adhering to proper injection protocols and thoroughly documenting adverse events is crucial for enhancing patient safety.