Ultrasonographic features of nonvascular complications of hyaluronic acid fillers: a retrospective study at a reference center for dermatologic ultrasonography.

Hyaluronic acid filler injections have been associated with early, temporary, and delayed-onset complications. High-resolution ultrasound with Doppler analysis has been increasingly used to detect and identify such complications. We comprehensively describe the most common ultrasonographic findings of nonvascular complications associated with hyaluronic acid filler injections. This retrospective, cross-sectional, observational study was conducted at a reference center for dermatologic ultrasound in Bogotá, Colombia. Ultrasound reports documented the ultrasonographic findings of nonvascular complications of hyaluronic acid filler injections. Fifty-two complications were documented in a cohort of 50 patients (women, 88%). The infraorbital region was the most common site affected (23%), followed by the nasolabial region (22%). The Tyndall effect was the most common complication (25% of all), followed by changes in rheology (21%) and pseudosarcoidal (foreign body granuloma) reaction (15%). The Tyndall effect stood out for its distinctive ultrasonographic characteristics. We discuss the ultrasonographic findings and pathogenesis of other complications, including filler migration, early hypersensitivity, aseptic abscess, overcorrection, and filler material interaction. The clinical presentation of hyaluronic acid filler complications can be confusing, delaying timely diagnosis and treatment. High-resolution ultrasound with Doppler analysis is a valuable tool for avoiding unnecessary treatments and ensuring timely diagnosis and treatment.