## 4 Discussion  
The use of highly-active retroviral therapy (HAART) with protease inhibitors, first described in the United States in 1997, has demonstrated a significant clinical benefit in the treatment of HIV infection [1,2]. Within one year of its introduction, mortality rates dropped by 45% and there was a significant decline in the number of reported AIDS-defining diseases. However, as in most chronic pharmacological therapies, there are several side effects, such as diarrhea, renal calculi, nausea and period paraesthesia [3,4]. One medication-associated condition that has become prevalent among HIV-infected patients is HIV-associated lipodystrophy, a syndrome characterized by abnormal fat metabolism and deposition. Broadly speaking, lipodystrophy syndrome is composed of three components: lipoatrophy (subcutaneous fat loss in the face, limbs and buttocks), lipohypertrophy (fat accumulation in the abdomen, dorso-cervical or cervical fat pads) and metabolic disturbance (insulin resistance, hypercholesterolemia and hypertriglyceridemia) [6]. Facial lipoatrophy, also known as facial wasting, is the most distressing manifestation for HIV patients. It can be stigmatizing, severely affecting quality of life and self-esteem, and it may result in reduced antiretroviral adherence [5]. A number of medical, pharmacological, and surgical therapies are used to treat HIV lipodystrophy. In addition to physical exercise and nutritional counselling to prevent the loss of lean body mass, anabolic steroid hormones, testosterone and human growth hormone have increasingly been used in these patients, with varied success and significant side effects [6]. Therefore, ever-increasing numbers of HIV patients receiving HAART are presenting to aesthetic physicians requesting non-surgical procedure to ameliorate the unwanted side effects of their treatment protocol such as facial wasting and buffalo hump. As stated by [PERSON] et al., HIV+ patients are considered a very high-risk group in terms of susceptibility to infections [27,28]: probably due to this reasons, physicians are often afraid to treat this patient population. Figure 10: MRI of Caucasian male patient from Figure 8 showing bilateral collection of semi-fluid material. However medical literature shows that facial fillers are a reasonable option when facial lipoatrophy is the only stigmata of lipodystrophy; [PERSON] et al. performed a systematic review to determine the safety and efficacy of permanent and semipermanent dermal fillers to treat the visible effects of HIV-associated facial lipoatrophy [18]. They affirmed that the small number of well-designed studies limited the ability to draw firm conclusions; however, polylactic acid and polyacrylamide gel were the dermal fillers most used and the studies cited by the authors showed that these fillers do not tend to cause serious short-term adverse events [18]. In the present retrospective study, the authors investigated the complication rates of non-surgical aesthetic procedures in HIV+ patients in a long-range period, from 2008 to 2020. In the paper released by [PERSON] and [PERSON] regarding the complications of minimally invasive cosmetic procedures (considering non-infected patients), bruising, erythema and pain were found to be the most common complications with injectables [20]. In the present cohort of patients the most common transient and self-resolved complications were also bruising and redness. Infection was never observed with HA and CaHA fillers; in patients treated with polyacrylamide hydrogel, early complications were similar to those of HA and CaHA, with the exception of small palpable non-visible nodules in 13 patients over 42 (30.9%), which persisted at 5 years follow-up. Three cases of late-onset complications, one gel induration and two abscesses were also recorded (7.1%). In the medical literature, the use of polyacrylamide hydrogel filler has shown contrasting results.