Perioral leukoderma simulating vitiligo from use of a toothpaste containing cinnamic aldehyde

Area of Science:

• Dermatology
• Toxicology

Background:

• Perioral leukoderma can mimic vitiligo, presenting diagnostic challenges.
• Identifying external triggers is crucial for managing pigmentary disorders.

Observation:

• A 25-year-old woman presented with perioral leukoderma.
• Patch testing revealed a delayed depigmentation reaction to cinnamic aldehyde.
• No pigmentary changes were noted with neomycin sulfate (allergic) or nonanoic acid (irritant) patch tests.

Findings:

• Cinnamic aldehyde in toothpaste was identified as the causative agent for leukoderma.
• Depigmentation occurred three months post-patch test application of cinnamic aldehyde.
• Discontinuation of cinnamic aldehyde-containing toothpaste led to resolution of perioral hypopigmentation.

Implications:

• Cinnamic aldehyde is a potential contact allergen causing leukoderma.
• Patch testing is valuable for diagnosing contact-induced pigmentary changes.
• Awareness of cosmetic and oral care product ingredients is important for dermatologists and patients.