title: Superficial dermal injection of hyaluronic acid soft tissue fillers: comparative ultrasound study.
abstract: BACKGROUND
  Superficial dermal injection of hyaluronic acids (HAs) has not been well studied.
  
  
  OBJECTIVE
  To study HAs injected into the superficial dermis using ultrasound examination and measurements, to evaluate induration and pain, and to examine histology.
  
  
  METHODS
  Three commercial HAs were injected into the superficial dermis (0.2 mL). The HAs used were a biphasic gel, a monophasic monodensified gel, and a monophasic polydensified gel. Ultrasound measurements and images were obtained, pain assessed, and biopsies performed at 7 days.
  
  
  RESULTS
  Participants experienced pain from the HAs that did not contain lidocaine. After 8 days, the biphasic HA papules appeared erythematous, with two-thirds reporting the biphasic HA papules as tender. Ultrasound demonstrated superficial placement of HA gels in the upper dermis. The gels each exhibited unique characteristic patterns on ultrasound. Skin biopsies of the superficial dermal placement confirmed earlier patterns. Superficial placement of the biphasic product is associated with tenderness and an eosinophilic inflammatory infiltrate.
  
  
  CONCLUSIONS
  Superficial placement of HAs is possible, as demonstrated by ultrasonography. Gels that do not have lidocaine within them are more painful. Injection of biphasic HA gels superficially in the dermis is associated with clinical erythema and tenderness and histology showing an eosinophilic infiltrate.
authors: MedImage, Geneva, Switzerland.
authors: Patrick
authors: P
authors: Micheels
authors: Stephanie
authors: S
authors: Besse
authors: Timothy C
authors: TC
authors: Flynn
authors: Didier
authors: D
authors: Sarazin
authors: Yoel
authors: Y
authors: Elbaz
mesh_terms: D000328:Adult; D003357:Cosmetic Techniques; D005260:Female; D005782:Gels; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement
chemical_list: D005782:Gels; D006820:Hyaluronic Acid