Managing adverse events associated with botulinum toxin type A: a focus on cosmetic procedures

Botulinum toxin A (BTXA) has become a widely used drug in cosmetic dermatology, not only to treat focal hyperhidrosis but also hyperkinetic facial lines, platysma bands, décolleté bands, and other skin features. The spectrum of possible adverse effects of BTXA is broad but fortunately those that have been observed with cosmetic use of this product are generally mild and transient. The major tools for preventing adverse effects from BTXA are knowledge and skill. Use of correct injection techniques is mandatory since most unwanted effects are caused by incorrect technique. Knowledge of the target structures, e.g. the facial and extrafacial muscles, allows physicians to select the optimal dose, time and technique. The most common adverse effects are pain and hematoma. In the periocular region, lid and brow ptosis are important adverse effects. Adverse effects such as pain, hematoma, ecchymosis, and bruising may also occur in the upper and lower face and at extrafacial sites. Other possible adverse effects seen in other indications that the user of BTXA in cosmetic dermatology should be wary of include induction headaches and possible interaction with concomitant medications. Induction of neutralizing antibodies due to cosmetic BTXA treatment has not been observed. This article also outlines recommendations regarding use of BTXA. Of these, the most important for avoiding most unwanted adverse effects are the proper techniques of dilution, storage, and injection, as well as the careful exclusion of patients with any contraindications. Pain, hematoma, ecchymosis, and bruising can be prevented by cooling the skin before and after BTXA injection. Upper lid ptosis may be partly corrected using apraclonidine or phenylephrine eyedrops. If simple rules relating to the indications for and application of BTXA are followed, this is a safe and effective drug in cosmetic dermatology.