INTRODUCTION
Polyacrylamide hydrogel is a non-degradable, well-characterized filler agent, which becomes intimately integrated with its surrounding host tissue through vessel-ingrowth.1 Aquamid® (Contura International A/S, Denmark) is a 2.5% polyacrylamide hydrogel that has been used in the cosmetic industry for the past 10 years, where it has been injected into facial dermal and subcutaneous tissues to augment lips and eradicate wrinkles, scars, or other cavities.2-6 During this time it has been observed that the gel, just like other foreign body implants7 carries the risk of being invaded by contaminating normal skin bacteria like Propionibacterium acnes and Staphylococcus epidermidis. It has long been known that these bacteria can grow within implants, such as prostheses, and give rise to a low-grade chronic infection and biofilm formation,7,8 but it is only in recent years that the aesthetic society handling gel fillers has become aware of this problem.8-10 These bacteria are normally considered non-pathogenic, because they live unattended within skin keratin layers, hair follicles or sebaceous glands for long periods of time, but when they are accidentally injected into sites like dermal or subcutaneous tissues, these bacteria can survive within the gel and cause infection. Clinical symptoms of these infections (swelling and pain) depend on the onset after injection, type and number of bacteria injected, site (lips vs other sites), and size of gel bolus. They may set in immediately or up to one year after the injection, but usually they occur after 1-2 weeks.8,11
A thorough rinse of the injected site is not sufficient to avoid this contamination, which occurs during the injection process. The bacteria are typically deeply seated within hair structures and glands, ready to be led into the gel injection site by the needle. With the purpose of reducing these soft-tissue infections, prophylactic antibiotics were introduced into our clinic in 2007.
The overall purpose of this retrospective study has been to evaluate whether prophylactic administration of relevant antibiotics had any effect on complication rate. We present a consecutive series of 657 subjects that have been divided into two groups: group 1 receiving prophylactic antibiotics prior to gel injection (n=161) and group 2, receiving no prophylaxis before gel injection (n=496).
PATIENTS AND METHODS
A total of 657 subjects (605 women and 52 men) were injected by the same physician using the same injection technique, from August 28th 2001 to September 15th 2011. Injection sites included lips (n=422), glabella (n=95), and nasolabial folds, mentolabial folds, wrinkles around the mouth, philtrum and forehead, cheeks, chin, nose, defects and scars (n=140). Prophylactic antibiotic treatment (a combination of azithromycin, 500 mg, and moxifloxacin, 400 mg) was introduced as standard procedure from September 2007. The subjects were instructed to administer antibiotics as a single
