Making Sense of Late Tissue Nodules Associated With Hyaluronic Acid Injections

Area of Science:

• Dermatology
• Aesthetic Medicine
• Immunology

Background:

• The exact cause of delayed-onset tissue nodules (DTNs) following hyaluronic acid (HA) injections remains unclear.
• DTNs are a potential complication of aesthetic facial treatments using HA fillers.

Purpose of the Study:

• To develop a comprehensive theory explaining the development of DTNs.
• To establish guidelines for preventing and treating DTNs associated with HA fillers.

Main Methods:

• A consensus panel of multidisciplinary and international experts was convened.
• The panel addressed 20 questions regarding DTN pathogenesis, aiming for 75% agreement.

Main Results:

• Consensus was achieved on 16 out of 20 questions, providing a foundation for a DTN classification and treatment guide.
• Key factors identified in DTN pathogenesis include the filler material, presence of pathogens, and inflammatory responses.

Conclusions:

• DTNs are believed to be initiated by infection, with a subsequent variable immune response.
• The degradation of high molecular weight HA to low molecular weight HA (LMWHA) can enhance local inflammation, especially in the presence of bacteria.
• Practitioner hygiene, patient hygiene, and prompt treatment of systemic infections are crucial for preventing DTNs.