D2.423 - Occupational sensitisation to Chrysonilia sitophila in an asthmatic patient with nasal polyposis
Case report
Background
Demonstration of the occupational cause of an allergic disease often requires extensive investigation despite a lack of adequate tools.
We hereby present a case of occupational mould allergy diagnosed using an interdisciplinary approach.
The clinical history and occupational investigation guided environmental sampling, skin testing (ST), mycology and immunological investigations.
Dicsussion
A 45-year-old man presented with persistent cough and nasal symptoms refractory to corticosteroids. The patient had a 20-year history of asthma and nasal polyposis (NP), treated with beclometasone dipropionate/formoterol fumarate, montelukast and mometasone furoate/olopatadine. Occupational anamnesis revealed he was employed as a maintenance technician for professional coffee machines. He performed daily maintenance on 10 machines, including handling coffee residues and cleaning the machinery.
Prick-to-prick ST were negative for pure coffee grounds but positive for moldy grounds in 2017 (6 mm), confirmed twice in 2023 (8 mm). ST were negative for commercial fungal extracts (Alternaria, Aspergillus). Mold-specific IgE was undetectable with singleplex assays (Penicillium, Cladosporium, Aspergillus, Alternaria) and with an allergen chip containing 60 fungal extracts and molecules (Fungiplex).
Mycological investigation of the coffee grounds led to Chrysonilia sitophila (Cs) through culture, macro/micro identification, and molecular biology. This thermoresistant Ascomycete is a recognized occupational allergenic source in the wood and cork industries; the first case in the coffee industry was described in 2010.
Taken together, the diagnostic investigations pointed to Cs in coffee residues as the causal agent of occupational respiratory disease. The patient was declared unfit for professional coffee machine maintenance. Reassessment 6 months after the end of the occupational exposure showed respiratory improvement, allowing for a reduction in inhaled treatments.
Conclusion
This case highlights the need for in-depth investigations of suspected occupational exposure as a cause of allergic diseases. Here, an interdisciplinary approach allowed identification of Cs as the culprit species in occupational mold exposure responsible for chronic respiratory diseases. Future perspectives include the development of diagnostic tests using Cs, information on the occupational risks of specific molds, and the development of appropriate prevention protocols.
