Patch testing with frullania during a 10-year period: hazards and complications

Area of Science:

• Dermatology
• Allergology
• Plant Contact Dermatitis

Background:

• Contact dermatitis is a common skin condition, with plant-derived allergens posing a significant challenge.
• Frullania species, particularly Frullania dilatata and Frullania tamarisci, are known allergens prevalent in Europe.
• Understanding the specific allergenic potential and cross-reactivity of these species is crucial for accurate diagnosis.

Purpose of the Study:

• To investigate the diagnostic utility and potential risks associated with patch testing for Frullania-induced contact dermatitis.
• To determine if cross-reactivity exists between the two most common European Frullania species.

Main Methods:

• Retrospective analysis of patient cases suspected of Frullania intolerance.
• Review of patch testing results and clinical outcomes.
• Assessment of adverse reactions, specifically active sensitization, following patch testing.

Main Results:

• Frullania contact dermatitis primarily impacts individuals in rural environments.
• Frullania dilatata and Frullania tamarisci do not exhibit cross-reactivity, necessitating individual testing.
• A significant proportion (9 out of 37) of tested patients developed active sensitization from the patch tests.

Conclusions:

• Patch testing for Frullania intolerance is indicated when suspected, testing both Frullania dilatata and Frullania tamarisci.
• Routine patch testing with Frullania species poses a risk of inducing active sensitization.
• Targeted and cautious application of patch testing is recommended over routine screening due to safety concerns.