Bruising presents as a non-elevated, rounded or irregular, blue or purplish patch. Bruising is often a tell-tale sign that you have had something done and can lead to some embarrassment and unsolicited questions in addition to the negative cosmetic effect of a bruise.

Localized reactions such as bruising are by far the most common adverse event encountered with procedures such as dermal filler or botulinum toxin injections. The incidence is variable and dependent on many factors. One study reports the incidence of bruising following dermal fillers to be between 19 and 24 percent, and another study reports the incidence as high as 68 percent.

Older people with thin and fragile skin and slower repair mechanisms as well as people who are malnourished may be in a higher risk group; vitamin C deficiency and iron deficiency increase the risk of bruising and prolong healing time.

Alcohol increases increases risk of bruising. You should avoid alcohol 24 hours prior to treatment. Many prescribed medications, such as aspirin, clopidogrel, warfarin, non-Vitamin K-dependent oral anticoagulants (e.g., dabigatran, apixaban, and rivaroxaban), heparin, and Lovenox all affect blood clotting and will increase the risk of hemorrhage and bruising. These are often prescribed in atrial fibrillation, thromboembolic disease, mechanical heart valves, and in patients with a high risk of or previous cardiovascular or cerebrovascular infarction. These medications should not be stopped without your specialist's advice and should not be discontinued for an aesthetic procedure. If aspirin is being taken for another indication, such as pain or colon cancer prevention should be avoided for two weeks before the treatment is performed. Similarly, non-steroidal anti-inflammatory (NSAIDS) medications (e.g., ibuprofen, naproxen, diclofenac, celecoxib, and meloxicam) should be avoided for a similar period of time. 

Over-the-counter herbal and vitamin supplements are becoming increasingly common and can have an influence on clotting time and increase the risk of bruising. In particular, fish oils, omega-3 fatty acids, garlic, high-dose Vitamin E, gingko biloba, and St. John’s wort may all lead to greater bruising. The consensus is that these should be avoided for two weeks before injections.

The topical application of arnica, as well as taking oral arnica and/or bromelain can lead to a reduction in the development of a bruise and may also increase the speed of resolution. Oral Arnica 30c can be taken 3 times per day starting the morning of the procedure and continued for 3 additional days. Bromelain is an enzyme derived from pineapple that can be taken at a dose of 200 to 400mg three times per day to speed healing and help the body clear metabolic waste following an injury.

Vigorous exercise and extreme heat can increase blood pressure and blood flow and aggravate any bruising that is developing; therefore, exercise should be avoided for the first 24 hours following an aesthetic procedure. 

Finally, if unacceptable bruising does develop, camouflage make-up may be applied. Persistent bruising may be amenable to laser treatment, though bruising usually resolves on it's own in healthy individuals within 10 to 14 days, though it is recommended that all injections are done more than 2-4 weeks before any big event or vacation. The application of cold packs within the first 48 hours followed by heat can aid resolution. Sun avoidance is critical initially to limit the risk of persistent skin staining.