Late Onset Foreign Body Reaction due to Poly-L-Lactic Acid Facial Injections for Cosmetic Purpose.

Area of Science:

• Dermatology
• Plastic Surgery
• Pathology

Background:

• Poly-L-lactic acid (PLLA) is a well-established injectable filler for facial rejuvenation and treating lipoatrophy.
• Its safety and efficacy profile is generally considered robust for cosmetic applications.

Observation:

• A 57-year-old female presented with deep-seated nodules on both cheeks 18 months after PLLA filler injections.
• The nodules were investigated via skin biopsy for diagnostic purposes.

Findings:

• Histopathological examination using hematoxylin and eosin stain revealed non-caseating granulomas in the dermis.
• These granulomas contained histiocytes surrounding central foreign bodies, consistent with a delayed inflammatory response.

Implications:

• This case highlights a rare instance of late-onset foreign body reaction to PLLA facial fillers.
• It suggests the possibility of delayed complications, even with widely used and proven cosmetic injectables.
• Further investigation into the long-term inflammatory potential of PLLA may be warranted.