Hypersensitivity pneumonitis related to a covered and heated swimming pool environment.

Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis is a lung disease caused by a large group of inhaled antigens of various sources. The most common HP occurring in the farm environment is classically caused by exposure to various thermophilic actinomycetes and fungi that can grow in the farm environment. Pullularia species and thermophilic actinomycetes have been involved in HP related to humidifier water and saunas. Our case illustrates the value of a site visit in the diagnosis of HP. During a visit to the covered and heated swimming-pool where our patient used to swim we could see that favourable conditions to fungal growth existed. To determine the possible aetiological agents of a suspected HP, cultures from several parts of the swimming-pool were taken. These cultures showed an intense growth of thermophilic actinomycetes, Neurospora and Aspergillus species. Precipitating antibodies against Neurospora species and Mycropolyspora faeni were detected. A case of HP related to a covered and heated swimming-pool environment is reported. Thermophilic actinomycetes and Neurospora species may be the causing agents.