Patch Testing to Carvone: North American Contact Dermatitis Group Experience, 2009 to 2018

Area of Science:

• Dermatology
• Allergology
• Toxicology

Background:

• Carvone, a common flavoring agent, is recognized as a potential cause of allergic contact dermatitis.
• Understanding the prevalence and characteristics of carvone sensitivity is crucial for clinical diagnosis and management.

Purpose of the Study:

• To determine the 10-year prevalence of patch test reactions to carvone.
• To analyze the demographic, clinical, and exposure characteristics of patients with confirmed carvone sensitivity.

Main Methods:

• Retrospective analysis of patch test data from the North American Contact Dermatitis Group (2009-2018).
• Inclusion of patients with positive patch test reactions to carvone (5% petrolatum).
• Comparison of demographics, reaction relevance, coreactivity, and exposure sources between carvone-positive and carvone-negative patients.

Main Results:

• A total of 24,124 patients were tested for carvone sensitivity, with 188 (0.78%) showing positive reactions.
• Carvone-positive patients were significantly more likely to be older than 40 years.
• Personal care products (46.3%) and food (14.3%) were the most common sources of exposure; 60.6% exhibited coreactivity with other fragrance/flavor allergens.

Conclusions:

• The prevalence of carvone sensitivity over a decade was 0.78%.
• Positive reactions were more common in females over 40, often presenting with facial dermatitis.
• A significant proportion of carvone allergies would be missed if not specifically tested for, highlighting its importance beyond common fragrance mixes.