Botulinum toxin (BTX) is a protein produced by the bacterium Clostridium botulinum, and is known to be extremely neurotoxic. It produces chemical denervation and temporary paralysis of the muscles. This action may not be complete for 2 weeks. Muscular function begins to return at approximately 3 months and is usually complete by 6 months.
Popularly known by one of its trade names, Botox ® or Dysport ®, it is used for various cosmetic procedures.
Cosmetic Indications:
Facial Wrinkles: Frontal region (Forehead), periorbital (Crow’s feet);
Glabellar frown lines (space between the eyebrows and above the nose);
Nasal wrinkles (“bunny lines”) and to increase nasal tip projection by paralyzing muscle that pulls down the nasal tip (Depressos septi nasi muscle);
Perioral wrinkles (the ones around the mouth) and depressor anguli oris (the muscle that lowers the corners of the lips downwards);
Nasolabial folds (levator labii superioris alaeque nasi): Although they reduce the nasolabial groove, they also diminish the elevation of the lip for smiling which is not an acceptable cosmetic outcome. Most injectors have abandoned this procedure;
Dimpled Chin (Mentalis muscle);
Neck wrinkles (Vertical platysmal bands and horizontal neck lines).
Side effects/Complications (highlighted):
Generalized reactions: nausea, headache fatigue, malaise, flu-like symptoms, and allergic reactions (with rashes at sites distant from the injection).
Systemic complications: The therapeutic use of BTX generally has been safe and well tolerated. However, there are reports of effects of BTX injections in muscles distant from the site of injection. There have been a few reports of increased jitter, generalized weakness, and botulism-like syndrome, even though these were rare and usually associated with some preexisting neuromuscular condition.
Local (and temporary) changes due to the percutaneous injection: pain, edema, redness of the skin (erythema), bruising (ecchymosis), headache, and short-term numbness (hypesthesia). Discomfort can be decreased by use of topical anesthetics (EMLA ®) before injection and the use of smaller gauge needles. Ice applied immediately before and after injection will further reduce the pain as well as the edema and redness (erythema) associated with an intramuscular injection. Ecchymosis (bruising) can be minimized by avoiding aspirin and non-steroidal anti-inflammatories agents for 7 to 10 days before injection.
Brow: brow ptosis: select patients well or inject brow depressors simultaneously. “Nicholson” brow: quizzical look. Inject small amounts into the fibers of the lateral forehead. Note that roughly 90% of the population has some degree of brow asymmetry even before Botox treatment.
Glabella: most common is drooping eyelid (ptosis of the upper eyelid), which occurs from 48 hrs up to 7 to 10 days after treatment, and can persist for up to 2 to 4 weeks. Treatment with α-Adrenergic agonists ophthalmic eye drops (apraclonidine; phenylepherine), repeated as necessary until ptosis disappears. Some authors believe that patients with previous frontal surgery are more likely to develop upper eyelid ptosis.
Crow’s feet: Reported complications in this area are bruising, double vision (diplopia), ectropion (turning out of the lateral lower eyelid, so that the inner face is exposed), and an asymmetrical smile caused by the toxin diffusing to zygomaticus major muscle (muscle responsible for smiling). To avoid these complications, inject at least 1 cm outside of the bony orbit or 1.5 cm lateral to the lateral canthus and do not inject close to the inferior margin of the zygoma. Violating these boundaries has on occasion also resulted in double vision (diplopia) due to medial migration of BTX and resultant paralysis of the lateral rectus muscle. If double vision (diplopia) occurs, covering or patching the eye will alleviate some of the double vision. If a patient has redundant skin, again be careful because the skin can end up folding on the zygomatic arch, producing an undesirable cosmetic result. Injections under the eye must be approached cautiously and should not be attempted if the patient exhibits a significant degree of scleral show pretreatment, if the patient has had significant surgery under the eye previously, if the patient has a great deal of redundant skin under the eye or a slow snap test of the lower eyelid indicating increased lid laxity. Deeper zygomaticus lines often connect to the lower crow’s feet lines. Treatment of the crow’s feet can paradoxically worsen the zygomaticus lines because the redundant cheek skin gravitates downward. Botulinum toxin for lateral canthal rhytids (crow’s feet) usually does not suppress tear production. However, decreased tear production after botulinum toxin injection for crow's feet is a possible complication and patients should also be advised of the small but definite risk of a temporary dry eye and keratitis (inflammation of the eye’s cornea). Due to weakening of the orbicularis oculi muscle (the muscle that surrounds the eyes), some patients can persist with residual nondynamic lines or present with infraorbital skin redundancy or inferior fat pad herniation. Although not the direct result of BTX and not associated with a change in function or shape of the eyelid margin, these anatomic concerns can be avoided with an adequate physical examination and correctly selecting the appropriate candidates as well as means for facial rejuvenation. Combining BTX with adjunctive therapy such as fillers is often necessary to address the patient’s aging anatomy appropriately.
Upper lip wrinkling/upper lip lines: An asymmetric smile, biting the inside of a flaccid cheek, difficulty with speech/gargling, and incompetence of the mouth manifest by drooling and dribbling are all possible complications of the overly enthusiastic use of BTX in the lower face. Treatment of the lip can result in flattening of the vermillion border secondary to atrophy of the orbicularis oris. This is easily corrected by adding a filler to the lip edge at the time of Botox treatment.
Depressor anguli oris (the corners of the lips): one must be extremely cautious not using BTX close to the mouth because of the danger of producing a flaccid cheek, an incompetent mouth or an asymmetric smile.
Mentalis: Injection into the mental fold area can easily produce an incompetent mouth and/or a asymmetric smile.
Neck (Vertical platysmal bands and horizontal neck lines): the use of these large doses has resulted in reports of difficulty swallowing (dysphagia) either due to diffusion of the toxin into the muscles of deglutition of the larynx or injection directly into the sternocleidomastoid muscle. Three to 4 days after injection, patients will note the onset of a moderate inability to swallow. Patients should be encouraged to change their diet to liquids and soft foods and should be reeducated about the temporary effect of BTX and the eventual and spontaneous improvement in swallowing. Meloclopramide hydrochloride (Reglan; Invamen, Dayton, NJ) stimulates motility of the upper gastrointestinal tract and perhaps can improve swallowing. Besides dysphagia, other reported complications that may occur (especially with the treatment of the vertical platysmal bands) are the weakness of the neck flexors and a change of the pitch of the voice (also hoarseness, loss of voice, and trouble saying words clearly).
Other unusual complications: metallic taste after BTX injection, Pseudoaneurysm (hematoma that forms as the result of a leaking hole in an artery) of the Frontal Branch of the Superficial Temporal Artery,
sarcoidal granulomas at the injection sites.
Resistance to Botox:
Immunoresistance to the botulinum toxin has been previously described as a decreased clinical effect of the toxin, which may result from the presence of circulating antibodies. To minimize immunoresistance, it is recommended that booster injections be avoided, that 3 months be allowed to elapse between injections, that total dosages be limited to less than 100 U per session, and that the smallest effective dose possible be used.
WARNING: Individuals who are pregnant, have egg allergies or a neuromuscular disorder are advised to avoid Botulinum toxin injections.
References:
1. Keen M, Blitzer A, Aviv J, et al. Botulinum toxin A therapy for hyperkinetic facial lines: results of a double-blind, placebocontrolled study. Plast Reconstr Surg. 1994; 94:94–9.
2. Klein AW. Complications, Adverse Reactions, and Insights with the Use of Botulinum Toxin. Dermatol Surg 2003;29:549–556.
3. Saeliw P, Preechawai P, Aui-aree N. Evaluating the effects of ice application on patient comfort before and after botulinum toxin type A injections. J Med Assoc Thai. 2010 Oct;93(10):1200-4.
4. Prado AC, Andrades PR. Caution in Using Botox in Patients with Previous Frontal Surgery. Plast Reconstr Surg. 2002; 109(4):1472-1473.
5. Arat YO, Yen MT. Effect of botulinum toxin type a on tear production after treatment of lateral canthal rhytids. Ophthal Plast Reconstr Surg. 2007; 23(1):22-4.
6. Ferreita MC. Salles AG, Gimenez R, Soares MFD. Complications with the Use of Botulinum Toxin Type A in Facial Rejuvenation: Report of 8 Cases. Aesth Plast Surg. 2004; 28:441–444.
7. Northington ME, Huang CC. Dry eyes and superficial punctate keratitis: a complication of treatment of glabelar dynamic rhytides with botulinum exotoxin A. Dermatol Surg. 2004; 30(12):1515-7.
8. Matarasso SL: Complications of botulinum A exotoxin for hyperfunctional lines. Dermatol Surg. 1998; 24:1249–1254.
9. Garcia A, Fulton E: Cosmetic denervation of the muscles of facial expression with botulinum toxin.
Dermatol Surg. 1996; 22:39–43.
12. Prado A, Fuentes P, Guerra C, Leniz P, Pamela W. Pseudoaneurysm of the Frontal Branch of the Superficial Temporal Artery. Plast Reconstr Surg. 2007; 117(6):2334-5.
13. Paloma V, Samper A. A Complication with the Aesthetic Use of Botox: Herniation of the Orbital Fat. Plast Reconstr Surg. 2001 Apr 15;107(5):1315.
14. Murray C, Solish N. Metallic Taste: An Unusual Reaction to Botulinum Toxin A. Dermatol Surg. 2003; 29:562–563.
15. Matarasso A, Christopher C. Botulinum Toxin. Plast Reconstr Surg. 2002; 115(5):62-65.
