Ultrasound-assisted management of filler-related complications: Report of a successful treatment of delayed-onset nodules related to polycaprolactone-based filler.

A 60-year-old woman underwent polycaprolactone-based filler injection in her midface. Four months later, she developed progressive swelling of midface after a self-limiting viral gastroenteritis. The diagnosis was "delayed-onset immune-mediated nodule formation triggered by a virus." Ultrasonography enabled us to efficiently treat her with a tailored intralesional corticosteroid injection method.