Indoor fungi, distribution and allergenicity

Modern houses in Western Europe contain a number of fungal biotopes in which mold allergens may develop: timber, food, feed, brick, plaster, wallpaper, paint, pets, window plants and dust, to name only a few. The allergens are present in spores as well as in mycelium, and are secreted in their environment. Current sampling results from the indoor air do not reflect total patient exposure. Of the 250.000 mold species present on earth, allergological test results could be found of about 140 (0.06%). Of the 98 fungal taxa listed from the indoor environment, 38 (39%) were tested for their allergenic potency. Genera investigated in 3 or more groups of patients showed positive skin reactions in 10 to 32% of the cases. Hence, fungal allergies are a significant public health problem. Unfortunately more than half a century of research on mold allergies has not led to an understanding of the exposure and sensitization of allergic patients in the indoor environment. Ecologically and clinically sound studies are urgently needed in the near future.