Persistent Hyperpigmentation Following Coretox Injection: A Review of Adverse Events Associated with Polysorbate 20

Area of Science:

• Dermatology
• Aesthetic Medicine
• Cosmetic Science

Background:

• Postprocedural hyperpigmentation is a rare complication of botulinum toxin type A injections.
• Coretox, a specific formulation of botulinum toxin type A, has been associated with three cases of persistent facial hyperpigmentation.
• The underlying mechanisms of this reaction require further investigation.

Purpose of the Study:

• To characterize the clinical presentation, imaging findings, and potential mechanisms of persistent facial hyperpigmentation following Coretox administration.
• To report the first documented cases of this adverse event linked to a specific Coretox batch.

Main Methods:

• Case series involving three female patients who received Coretox injections.
• Serial clinical photography and advanced imaging (QuantifiCare LifeViz) were utilized.
• Review of patient history, sun exposure, skincare, and concurrent medications.

Main Results:

• Three patients developed localized hyperpigmented macules 2-3 weeks post-Coretox injection.
• Imaging revealed elevated melanin and hemoglobin signals in affected areas.
• Hyperpigmentation persisted beyond one year despite various treatments, with all cases linked to Coretox batch E622080A.

Conclusions:

• Persistent facial hyperpigmentation is a potential complication of Coretox injections, possibly linked to polysorbate 20.
• Early recognition, patient counseling, and photoprotection are recommended.
• Further research into excipient-induced pigmentary changes is warranted.