[Acariasis due to dermanyssus gallinae (gamosoidosis) in Vienna (author's transl)].

Four cases of gamasoidosis (avian mite dermatitis) caused by Dermanyssus gallinae (De Geer 1778) were observed in a factory for optical instruments in Vienna. After removal of an infected pigeon nest outside one of the windows in a recess of the wall in front of a fan, no further skin lesions appeared. The darkening of the room during work hours could explain the activity of the mites during day time. Although gamasoidosis is mainly seen in rural areas, it is not infrequently encountered in urban settings and should always enter the differential diagnosis in the presence of pruriginous skin lesions not meeting all of the diagnostic criteria of scabies.