Association Between Sensitization to Mold and Impaired Pulmonary Function in Children With Asthma

Abstract

PurposeRecent data indicate that sensitization to mold contributes to the severity and persistence of asthma. In this study, we investigated the relationships between sensitization to mold and lung function parameters in children with asthma.MethodsWe retrospectively reviewed clinical data from 551 asthmatic subjects. We selected subjects who met clinical diagnostic criteria of asthma. Their spirometry, methacholine challenge tests, and measurements of blood eosinophils, serum IgE, eosinophil cationic protein (ECP) and fractional exhaled nitric oxide (FeNO) results were included. Skin prick testing (SPT) results with 13 common aeroallergens in Korea including house dust mites, animal dander, pollen, cockroach and mold were reviewed. Subjects were divided into 3 groups according to their SPT results. Subjects who showed no positive result to any aeroallergen were designated as group 1 (non-sensitized). Group 2 represented subjects who were sensitized to aeroallergens other than mold (other allergen-sensitized) and group 3 included subjects who were sensitized to mold allergens (mold-sensitized).ResultsAmong the 551 asthmatic subjects, 67 (12.2%) were sensitized to mold and 366 (66.4%) were sensitized to other aeroallergens. The log mean IgE levels were higher in groups 2 (5.96±1.14 IU/mL) and 3 (5.81±0.97 IU/mL) compared to group 1 (3.88±1.68 IU/mL). Blood eosinophils, ECP and FeNO concentrations were significantly higher in groups 2 and 3, but no significant difference was found between the 2 groups. The mean FEV1 value was significantly lower in group 3 (86.9±12.1%pred) than in groups 2 (92.0±14.8%pred) and 1 (93.4±15.4%pred). The log mean methacholine PC20 was significantly lower in group 3 (0.08±1.91 mg/mL) than in groups 2 (1.31±1.69 mg/mL) and 1 (2.29±1.66 mg/mL).ConclusionsWe observed a differential association between mold and other aeroallergen sensitization, and severity of asthma. Sensitization to mold is associated with lower lung function and increased airway hyper-responsiveness in children with asthma. Mold sensitization could be an important factor determining asthma severity particularly airflow limitation in children.

Taming Asthma in School-Aged Children: A Comprehensive Review

“…Approximately 12.2% of children with persistent asthma are sensitized to molds (33). There is a wide variety of indoor and outdoor molds and its allergenic proteins vary by mold species.…”

Does allergy explain why some children have severe asthma?

“…24,95,96 Frequency of sensitization and degree of skin-test positivity to Alternaria has been strongly linked to asthma severity, and exposure in those sensitized is associated with more frequent severe and life-threatening episodes of asthma. 98 There was no difference between the two groups in terms of incidence of rhinitis or eczema, FENO or blood eosinophil levels, suggesting the relationship between fungal sensitization and STRA is not merely due to increased atopic tendency. 98 There was no difference between the two groups in terms of incidence of rhinitis or eczema, FENO or blood eosinophil levels, suggesting the relationship between fungal sensitization and STRA is not merely due to increased atopic tendency.…”

“…67,96,97 A study of 566 children with asthma in South Korea found those sensitized to mould compared with those sensitized to other aeroallergens but not mould had significantly lower lung function and increased airway hyperresponsiveness. 98 There was no difference between the two groups in terms of incidence of rhinitis or eczema, FENO or blood eosinophil levels, suggesting the relationship between fungal sensitization and STRA is not merely due to increased atopic tendency. A similar study showed those sensitized to moulds compared with those sensitized to other aeroallergens but not moulds had a significantly lower FEV 1 and were more likely to have STRA, suggesting moulds may play a greater role in STRA than other aeroallergens.…”

“…104 Secondly, long-term colonization or infection of the airways with allergenic fungi could provide a persistent source of allergen exposure and trigger proinflammatory host defence mechanisms. 96,98,104,105 Severe asthma with fungal sensitization (termed SAFS) may represent a discrete phenotype of STRA, with properties similar to allergic bronchopulmonary aspergillosis (ABPA) in adults, and possible improvement with antifungal therapies. 24,104-106 SAFS is typically associated with worse inflammation than other phenotypes of STRA despite more asthma treatment.…”

The Effects of the Environment on Asthma Disease Activity

“…The most common species to which children are sensitized and exposed are Alternaria and Cladosporium (outdoor), Aspergillus and Penicillium (indoor) 43 . The prevalence of mold sensitization in children with persistent asthma is variable in the literature -ranging from 12% to 66% 44,45 . Qualitative assessments of fungal exposure in the form of mildew odor or visible mold have been linked to increased risk of allergic rhinitis and asthma 46 .…”