Contraindications to botulinum toxin injection include keloidal scarring, neuromuscular disorders (e.g., myasthenia gravis), allergy to constituents of botulinum toxin product, unrealistic expectations, and body dysmorphic disorder.
https://www.aafp.org/pubs/afp/issues/2014/0801/p168.html
Adverse Effects
Adverse effects are frequently moderate and self-limited. Therapeutic use of botulinum toxin reported more pressing adverse effects over the cosmetic practice; this may be due to the higher dosing required for therapeutic applications and possible complicated underlying conditions. Among the more minor complications, bruising, edema, or pain at the injection site can develop during aesthetic use. Flu-like symptoms can also occur. More uncommon complications include blepharoptosis and eyebrow ptosis, which is dependent on the injector. Eyelid ptosis transpires with the introduction of botulinum toxin is introduced into the glabella, procerus, and corrugator muscles with unintended dispersion into the levator orbicularis muscle. These unfavorable effects can serve up to three months. As the technique and skill for injections improve, the incidence of complications decreases. Allergic reactions are amongst the rare reported adverse effects. Symptoms may range from trivial to more severe rashes, and systemic anaphylaxis may also occur.
Other complications include:
- Headache
- Infection
- Cocked eyebrow
- Ectropion
- Decreased strength of eye closure
- Xerophthalmia
Contraindications
Botulinum toxin contraindications include:
- Neuromuscular disorders conditions like myasthenia gravis are indeed contraindications due to the risk of exacerbating muscle weakness[3][8].
- Botulinum toxin allergies: Allergy to any component of the botulinum toxin product is a valid contraindication[8].
- Body dysmorphic disorder These are considered relative contraindications due to the psychological aspects involved[8].
- Pregnancy: These are also contraindications due to the lack of sufficient safety data[3][7].
- Breastfeeding
- Amyotrophic lateralizing sclerosis myopathies
Adverse Effects:
- Common Adverse Effects: Bruising, edema, and pain at the injection site are common and typically mild[6][7].
- Flu-like Symptoms: These can occur but are less common[6].
- Blepharoptosis and Eyebrow Ptosis: These are known complications related to technique and can occur if the toxin spreads to unintended muscles[2][3].
- Other Complications: Headache, infection, and other issues like ectropion and xerophthalmia are mentioned, though they are less common[6][7].
- Technique and Skill:
- As noted, the incidence of complications decreases with improved technique and skill of the injector[2][3].
Citations:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7323272/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7874868/
[3] https://emedicine.medscape.com/article/1271380-overview
[4] https://www.webmd.com/drugs/2/drug-153465/botox-injection/details
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4664143/
[6] https://www.plasticsurgery.org/cosmetic-procedures/botulinum-toxin/safety
[7] https://www.mayoclinic.org/tests-procedures/botox/about/pac-20384658
[8] https://www.ncbi.nlm.nih.gov/books/NBK557387/