Before initiating biological therapy, chest CT is indicated as a means of initial evaluation of severe asthma. While its primary role is to identify potential differential diagnoses, it concomitantly provides information effectively contributing to asthma phenotyping. In routine practice, analysis focuses on bronchial wall thickening, of which the extent correlates with disease severity and degree of bronchial obstruction. In cases of severe asthma, absent wall thickening is unusual, and may prompt a search for either an alternative diagnosis, or potential comorbidities such as rhinosinusitis, which may be symptomatic. Assessment of expiratory air trapping is useful in the event of fixed obstructive ventilatory impairment, of which the extent correlates with the degree of bronchial obstruction. Pathobiology of mucus plugs, a phenotyping tool regarding T2 inflammation and a marker of severity, has recently drawn increased interest. The density of these plugs should be analysed, given that spontaneous hyperattenuation, most often within dilated bronchi, facilitates establishment of the diagnosis of allergic bronchopulmonary aspergillosis. To sum up, investigation of bronchial wall thickening, expiratory air trapping, and mucus plugs represent potential means of assessing treatment response.

Allergic fungal sinusitis (AFS)-like syndrome refers to clinical presentations resembling AFS that do not fully satisfy established diagnostic criteria. We report a case of AFS-like syndrome in a 33-year-old woman, characterized by the presence of fungal hyphae within eosinophilic mucin despite negative systemic allergy testing, and we evaluate the limitations of current diagnostic frameworks. This report further examines the shared immunopathological spectrum between AFS and allergic bronchopulmonary aspergillosis, highlighting the importance of an integrated clinical approach to fungal hypersensitivity disorders affecting both the upper and lower airways.

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.

Allergic bronchopulmonary aspergillosis (ABPA) is under-recognized in children with refractory asthma and may be obscured by concurrent respiratory infections. We describe a 10-year-old girl with poorly controlled asthma admitted with fever, productive cough, and wheezing. Investigations revealed marked peripheral eosinophilia (1.48 × 10⁹/L), markedly elevated total immunoglobulin E (1742 IU/mL), positive bronchoalveolar lavage (BAL) galactomannan, and positive BAL Aspergillus antigen. Multiplex respiratory polymerase chain reaction (PCR) detected Streptococcus pneumoniae, Haemophilus influenzae, and methicillin-resistant Staphylococcus aureus, whereas concurrent bacterial cultures, blood culture, fungal culture, and viral testing were negative. High-resolution chest computed tomography (HRCT) demonstrated diffuse ground-glass opacities and bronchial wall thickening without central bronchiectasis or mucus plugging. A. fumigatus-specific IgE was not available, precluding formal classification under contemporary diagnostic criteria. A. fumigatus IgM and IgG were positive on follow-up serology. After empirical antibacterial therapy with limited durable response, oral itraconazole was initiated with sustained clinical improvement, declining total IgE and eosinophils, and stable hepatic function. This presentation is best characterized as suspected early Aspergillus-related allergic airway disease rather than confirmed ABPA. The case highlights three lessons for infectious diseases clinicians: bacterial co-detection by multiplex PCR may anchor reasoning toward infection and delay recognition of allergic fungal airway disease; lower airway Aspergillus biomarkers are supportive but not diagnostic; and the absence of central bronchiectasis does not exclude early disease. Integrated clinical, immunologic, microbiologic, and radiologic reasoning is essential in pediatric refractory asthma.

Eosinophilia is a frequently encountered laboratory abnormality in pulmonary practice and is associated with a wide spectrum of respiratory diseases ranging from benign allergic conditions to severe systemic disorders. Eosinophils play a key role in host defense, particularly in parasitic infections, but are also central to the pathogenesis of various inflammatory and hypersensitivity lung diseases. The presence of eosinophilia in patients with respiratory symptoms often presents a diagnostic challenge due to the diversity of underlying etiologies and overlapping clinical features. The objective of this study was to review the causes, pathophysiology, clinical spectrum, diagnostic approach, and management of eosinophilia in pulmonary practice. A narrative review was conducted using literature from PubMed, Scopus, and Google Scholar. Relevant articles published in English were identified using keywords such as "eosinophilia," "pulmonary eosinophilia," "eosinophilic lung diseases," "asthma," and "hypereosinophilic syndrome." Original research studies, clinical guidelines, and review articles focusing on respiratory manifestations of eosinophilia were included in the study. Articles lacking clinical relevance or focusing exclusively on nonpulmonary conditions were excluded from the study. The selected literature was synthesized qualitatively to highlight key clinical and diagnostic aspects. Eosinophilia in pulmonary practice may result from a variety of conditions, including allergic diseases such as asthma and allergic bronchopulmonary aspergillosis, parasitic infections, drug reactions, autoimmune disorders, and primary eosinophilic lung diseases such as acute and chronic eosinophilic pneumonia. Clinical presentation varies widely, ranging from mild respiratory symptoms to severe hypoxemic respiratory failure. Peripheral blood eosinophilia, along with radiological findings and bronchoalveolar lavage analysis, plays a crucial role in diagnosis. A systematic approach is essential to differentiate between primary and secondary causes. Management strategies depend on the underlying etiology and often include corticosteroids, antiparasitic therapy, or targeted biologic agents in selected conditions. Eosinophilia represents an important diagnostic clue in respiratory medicine and requires a structured and comprehensive evaluation. Early identification of the underlying cause is essential for appropriate management and prevention of complications. Advances in understanding eosinophil biology and targeted therapies are likely to improve outcomes in eosinophilic lung diseases.