Background and objective: Espartosis is a type of hypersensitivity pneumonitis which frequently affects construction workers handling esparto fibres used as support material inside gypsum plaster. Exactly which agents produce this disease remains under discussion. The aims of this study were: a) to assess the possible etiologic role of the fungi colonizing esparto grass fibres and esparto itself in the genesis of this disease, and b) to describe the clinical characteristics of this disease in a large series of patients.
Patients and method: Twenty patients diagnosed of hypersensitivity pneumonitis due to esparto grass exposure were studied. Mycologic cultures of the esparto grass fibre samples provided by each patient were performed. Fungi and/or esparto were used for determination of specific IgG antibodies, specific skin tests and specific bronchial challenge tests.
Results: Most frequently isolated fungi in causal esparto samples were Aspergillus sp. (60%) and Mucor sp. (47%). Specific IgG antibody determinations and/or specific bronchial challenge tests showed antigenicity not only for Aspergillus sp. but also for non-fungi-contaminated esparto grass and other fungi such as Penicillium sp. or Mucor sp. These results were helpful for establishing a new etiologic approach to the diagnosis of this disease.
Conclusions: Aspergillus fumigatus is recognized as a causal agent in hypersensitivity pneumonitis due to esparto grass exposure; however, other antigenic sources such as Penicillium frequentans and other fungi, as well as esparto grass fibres, also appear to play a role in the genesis of this disease.