Lichen picker's dermatitis (Cladonia alpestris (L.) Rab.)

Area of Science:

• Dermatology
• Immunology
• Environmental Health

Background:

• Lichen picking is a seasonal occupation in northern Finland.
• Dermatitis is a common concern among individuals engaged in lichen picking.
• The specific causes and immunological responses related to dermatitis in this group are not well understood.

Purpose of the Study:

• To investigate the frequency of dermatitis in lichen pickers.
• To explore the immunological background of dermatitis associated with Cladonia alpestris exposure.
• To identify potential allergens responsible for contact dermatitis in this population.

Main Methods:

• A community-based study involving 164 lichen pickers.
• Epidemiological assessment of dermatitis prevalence.
• Epicutaneous and photo-epicutaneous testing with Cladonia alpestris and its fractions.
• Scratch and scratch chamber tests were also performed.

Main Results:

• 30 out of 164 lichen pickers reported dermatitis, primarily on hands and forearms.
• Allergic contact reactions to Cladonia alpestris were observed in 9 subjects.
• Three subjects showed positive photo-epicutaneous reactions, indicating photo-allergic potential.
• No immediate reactions were detected in scratch tests.

Conclusions:

• Cladonia alpestris can act as a contact allergen in lichen pickers, leading to dermatitis.
• Photo-allergic reactions may also contribute to skin issues in susceptible individuals.
• The study highlights the occupational health risks associated with lichen picking.