Mold allergies are becoming increasingly important among the population. Increasing amounts of fungal spores are analyzed in air-samples because of urbanization, industrialization of food products and climate change. Mold also grows indoor and hence lead to additional health complaints.

Alternaria alternata, and its only major allergen Alt a 1, is the most important fungus for allergy sufferers. Alternaria alternata can not only cause allergic symptoms but can also cause intensified asthmatic symptoms.

Besides Alternaria alternata, there are over 700 other species of the genus Alternaria. The influence of these other species on allergic symptoms is poorly understood.

Furthermore, prevalence and incidence of an allergy to Alternaria alternata among the Austrian population is not known. Estimates range between 1-5% among the Austrian population.

This study aims to further investigate the incidence and characteristics of an allergy to Alternaria in Austria. This will be investigated with the help of participants (50 Alternaria allergy sufferers and 20 non allergic participants), spore counts in Austria and crowd-sourced symptom data.

Inclusion Criteria:

• Participants will be healthy people over 18 years of age. Allergic participants should have an allergic reaction against Alternaria, visible in the Skin-Prick-Test. Furthermore symptom data in the pollen diary of the Austrian Pollen Information Service should be existing

Exclusion Criteria:

• Subjects participating in a pharmacological study, pregnant subjects and subjects with an existing infectious- and/or autoimmune disease

Participants are recruited with the help of advertisements on the social media pages of the Austrian Pollen Information Service and on the pollen diary app