<i>Aspergillus fumigatus</i> as a causative agent of a number of dangerous allergic diseases

Abstract Aspergillus fumigatus is a clinically important airborne fungal pathogen capable of causing a broad spectrum of respiratory disorders. Persistent exposure or airway colonization can provoke severe allergic diseases, particularly in patients with asthma or cystic fibrosis, whereas impaired immunity or pre-existing structural lung damage may allow the development of chronic or life-threatening invasive pulmonary aspergillosis. Accordingly, the aim of this review was to synthesize current evidence on the role of A. fumigatus in the development of allergic and non-allergic diseases, with particular emphasis on its pathogenic mechanisms, clinical manifestations, diagnostic approaches, treatment strategies, and preventive measures. A systematic search was conducted in PubMed, ResearchGate, Scopus, Web of Science, and Google Scholar, and data on disease course, diagnosis, and management were synthesized. A. fumigatus is a widespread fungus whose spores are abundant in the air and pose a particular risk to immunocompromised individuals. Its virulence factors include thermotolerance, toxin and allergen production, and resistance to oxidative stress. The fungus causes allergic diseases, such as allergic bronchopulmonary aspergillosis, hypersensitive pneumonitis, and severe asthma with fungal sensitivity, as well as non-allergic diseases, including invasive and chronic pulmonary aspergillosis. Infection primarily affects the respiratory system, presenting with cough, weakness, catarrhal symptoms, and haemoptysis. Disseminated infection can involve the brain (cerebral aspergillosis), eyes (endophthalmitis), bones (osteomyelitis), and skin (dermatitis). Diagnosis involves histological tissue examination for fungal hyphae, detection of fungal antigens in blood or respiratory samples, measurement of specific immunoglobulin E, skin tests, and imaging studies. Antifungal and antiallergic drugs are the mainstay of treatment; in case of complications, surgical treatment is performed. To prevent aspergillosis, it is necessary to identify and inform risk groups; control air humidity; and wear masks in places of high risk of infection. A. fumigatus is a dangerous mycosis that causes severe allergic and non-allergic diseases, mainly in people with weakened immune systems.