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Updated: Jul 12, 2026

Induction and Monitoring of Active Delayed Type Hypersensitivity (DTH) in Rats
Published on: July 19, 2007
Persistent delayed-type hypersensitivity reaction to injectable non-animal-stabilized hyaluronic acid
Sarah Tuttleton Arron1, Isaac M Neuhaus
1Department of Dermatology, University of California, San Francisco, CA, USA.
Objective:
Injectable hyaluronic acid is a glycosaminoglycan used for soft-tissue augmentation. A number of products that are not Food and Drug Administration (FDA) approved for use in the United States are used commonly in Europe. We report a case of persistent delayed-type hypersensitivity to injected non-animal-stabilized hyaluronic acid. The patient was initially injected in Europe with a non-FDA-approved filler but traveled to the United States for evaluation of this adverse reaction.
Methods:
A case of adverse reaction to non-animal-stabilized hyaluronic acid is described. An overview of selected hyaluronic acid filler products is provided.
Results:
The patient developed persistent facial edema after injection of hyaluronic acid filler to the melolabial folds, glabella, lips, and perioral rhytids.
Conclusion:
Injectable hyaluronic acid can be associated with a variety of complications including immediate and delayed-type hypersensitivity reactions. Physicians should be familiar with products used in other countries, as patients may present for evaluation following adverse reaction to fillers obtained abroad or from American physicians using non-FDA-approved products.
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