Asthma is a chronic condition characterized by inflammation throughout the entire bronchial airways. Recent findings suggest that ventilation inhomogeneity and small airway dysfunction (SAD) play a particularly significant role in asthma development and clinical manifestations. Obesity is a considerable risk factor for asthma development and morbidity in children and adults. A growing body of evidence suggests that SAD is linked to more severe asthma and poor asthma control in obese patients. However, the knowledge about the relationship between peripheral airway compromise and obesity in asthma is limited, mainly because of the historical lack of access to non-invasive assessment methods for studying SAD. Conventional lung function measurements, like spirometry, cannot accurately assess small airway function. However, in recent years, new specialized tests available in outpatient settings have been found to distinguish SAD from large airway obstruction more accurately compared to spirometry. Therefore, understanding the degree of peripheral airway implication in the underlying pathology is critical for effective asthma control and therapeutic decisions. This review highlights recent findings on the impact of SAD on asthma patients who are obese. Additionally, it explores how new diagnostic methods, such as impulse oscillometry (IOS), may be used in outpatient settings to detect small airway impairment in obese asthma at an early stage, potentially leading to improved asthma treatment.

Non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is characterized by adult-onset asthma, chronic rhinosinusitis with nasal polyps (CRSwNPs), and aspirin/NSAID hypersensitivity, presenting recurrent asthma exacerbation and poor clinical outcomes. Patients with NERD have heterogeneous clinical phenotypes/endotypes, and the management of NERD remains challenging. Dysregulation of arachidonic acid (AA) metabolism and persistent eosinophilic airway inflammation are the major pathogenic mechanisms in the upper and lower airways of NERD. To date, increased levels of urinary leukotriene E4 (uLTE4) [a terminal metabolite of the lipoxygenase (LOX) pathway] have been the most relevant biomarker for NERD. It is demonstrated that mast cells, platelets, and epithelial cells can amplify upper and lower airway inflammation in NERD, and several potential biomarkers based on these complicated and heterogeneous mechanisms have been suggested. This review summarizes potential biomarkers for application in the management of NERD.

In Europe, allergen products from different manufacturers can be labeled using the same unit with yet different definitions of that unit, which may cause confusion, as is the case for the index of reactivity (IR). In this context, house dust mite (HDM) Staloral 300 IR/mL, from Stallergenes Greer, and HDM Osiris 300 IR/mL, from ALK-Abelló, were characterized in vitro. Qualitatively, namely in terms of protein and allergen profiles, the two products were similar. Quantitatively, and despite the same 300 IR/mL labeling, the two products were shown to have different biological potencies, with HDM Staloral 300 IR/mL displaying a 2.4 times higher total allergenic activity (TAA) than HDM Osiris 300 IR/mL. This higher biological potency of HDM Staloral 300 IR/mL was paralleled by higher allergen and protein contents, namely 1.5 times more Der p 1 and Der f 1, 3.0 times more group 2 allergens, 2.7 times more Der p 23, and 1.8 times more protein. In contrast, HDM Staloral 300 IR/mL was shown to contain far fewer culture medium-derived proteins than HDM Osiris 300 IR/mL.