Background Children with asthma are frequently sensitised to fungi and recent observations suggest that fungal sensitisation may be associated with more severe asthma in children.^1,2 Aspergillus fumigatus airway colonisation in adults with asthma is associated with reduced lung function.³ There is a paucity of data onfungal colonisation in children with asthma. The role of fungi in exacerbation prone asthma has not been previously investigated. Our study aim was to evaluate the association between fungal airway colonisation and exacerbation prone asthma in children.

Methods Children aged 5–16 years with stable asthma who attended for a routine hospital outpatient appointment and children with an acute exacerbation of asthma who attended for urgent care to an acute admissions unit were recruited to the study. We obtained a sputum sample either via nebulisation with hypertonic saline in children with stable asthma or nebulisation with 0.9% saline in children with acute asthma. Sputum culture was focused to detect filamentous fungi, in particular Apergillus and Penicillium species.^3,4 Culture and sensitisation results were compared with clinical assessment data.

Results Fifty five children were recruited to the study; 26 with acute asthma and 29 with stable asthma (17 BTS step 4–5). There was no difference in demographics between the two groups (Table 1). Sixteen children (29%) were culture positive for filamentous fungi, either Aspergillus fumigatus (81.3%) or Penicillium (18.7%). One child with stable asthma harboured two different filamentous fungi, A. niger and A fumigatus. Children with acute asthma were more likely to be culture positive for filamentous fungi than children with stable asthma (42.3%, n = 11 v 17.2%, n = 5 respectively, p = 0.041). Of the five children with stable asthma who were culture positive for filamentous fungi, three were BTS step 4–5.

Conclusions Significantly more children with acute asthma had filamentous fungi isolated from their sputum compared to children with stable asthma. Aspergillus fumigatus was the most common fungus isolated. The potential role of fungal airway colonisation in triggering asthma attacks in children merits further investigation.

References 1 Castanhinha S, Sherburn R, Walker S, et al. Pediatric severe asthma with fungal sensitization is mediated by steroid-resistant IL-33. J Allergy Clin Immunol 2015;136:312–322

2 Vicencio AG, Santiago MT, Tsirilakis K, et al. Fungal sensitization in childhood persistent asthma is associated with disease severity. Pediatr Pulmonol 2014;49:8–14

3 Fairs A, Agbetile J, Hargadon B, et al. IgE sensitization to Aspergillus fumigatus is associated with reduced lung function in asthma. Am J Respir Crit Care Med 2010;182:1362–8

4 Agbetile J, Fairs A, Desai D, et al. Isolation of filamentous fungi from sputum in asthma is associated with reduced post-bronchodilator FEV1. Clin Exp Allergy 2012;42:782–91