Fibrotic reaction to hyaluronic acid fillers in the face.

Background: Hyaluronic acids (HAs) can have very different actions not only depending on injector and host factors but also depending on their molecular weight. Whereas short chain HA has immunological activity long chain HA influences fibroblasts and may stimulate them to produce collagen. Although this is generally thought to be a positive feature it may be disadvantageous in certain localizations. Patients and Methods: We have encountered 23 patients who developed fibrous tissue next to the nasolabial folds accentuating them and becoming very obvious while smiling. Hyaluronidase injection did not reduce this mass. Results: Intralesional triamcinolone acetonide injection led to rapid improvement. Discussion: Fibrotic tissue reaction not responding to hyaluronidase may be the result of HA injection and can effectively be treated with intralesional steroid injection [ABSTRACT FROM AUTHOR]