“…Between 1 and 9.8% of the negative patients may, however, show evidence of hypersensitivity reactions after collagen injection, encompassing edema, erythema, skin induration, and local pruritus [13]. Biopsy specimens from injection sites usually show typical foreignbody granulomas [13,14]. In addition, systemic adverse reactions have also been described [13,15,16,17,18].…”