Aeroallergen sensitization in pediatric allergic rhinitis in Singapore: Is air‐conditioning a factor in the tropics?

Abstract

Singapore is a unique blend of a tropical environment with a high standard of hygiene and public health care. The objective was to define the prevalence, clinical characteristics, and environmental risk factors of specific aeroallergen sensitization in pediatric allergic rhinitis patients in this unique environment. The method adopted was a retrospective analysis of allergic rhinitis patients, undergoing aeroallergen skin prick testing (SPT), in the outpatient specialty clinic of the KK Children's hospital, from July 2001 to June 2002. A total of 202 patients were included, 161 (80%) males, 167 (83%) Chinese, age mean 7.6 yr (range 2-14 yr). The most prevalent clinical symptoms were: watery rhinorrhea 61%, blocked nose 61%, sneezing 52%, snoring 17%, and epistaxis 12%. SPT results were positive for house dust mites in 97% of children, pets (20%), molds (19%), pollens (15%), and kapok (10%). Mold sensitization was significantly more prevalent in households without air-conditioning (aircon), 49% vs. 10% with aircon (odds ratio 9.4, 95% CI 3.8-22.9). Polysensitization (sensitization to three or more allergens) was similarly more prevalent in households without aircon, 51% vs. 14% with aircon (odds ratio 6.4, 95% CI 2.8-14.7). It was concluded that indoor aeroallergen sensitization is the major associated factor with clinical allergic rhinitis in children in Singapore. Patients living in households without air-conditioning are at increased risk of mold sensitization and polysensitization.

Pets and the development of allergic sensitization

“…None of the three reported for allergic sensitization. In the rhinitis case series from Singapore, there was no association between cat or dog ownership and sensitization to the pet [26]. Again, these studies have shown inconsistent results for cat ownership, with fewer results but more consistency for dog ownership.…”

“…For allergic sensitization, no study found an increase in risk with pet owners, but the patterns of pet ownership associated with a decrease were varied (cats [14], dogs [16], and any feathered or furred pet [17]). Table 3 summarizes asthma case-control studies and asthma case-only studies [19][20][21][22][23][24][25][26]. For the two asthma/ rhinitis case-control studies, there was a decrease in the risk for sensitization to cat with higher Fel d 1 levels [20,21] or cat ownership [22].…”

Prevalence of Fungal Allergens in Respiratory Allergic Patients in Ahvaz City, Southwest Iran

“…Differences in the rate of positive SPT can be due to various factors such as number of allergens tested, climatic region and age of patients. With regard to optimum growing conditions, including high humidity for molds (28,29), Unexpectedly, this particular allergy was also found in hot and dry regions, like Saudi Arabia (6) and Kuwait (9,30), It might be associated with increasing the use of air conditioners inside the houses which make good environment for molds to grow and increase exposure to their allergens (26,28).…”

“…Higher rates of sensitization to molds are found in tropical countries like Singapore and Malaysia (26,27). In a study on 85 patients with allergic rhinitis, in Malaysia, prevalence of allergy to Alternaria and Aspergillus were 12.9% and 12.2%, respectively (27).…”

Assessment of mold concentrations in Singapore shopping centers using mold-specific quantitative PCR (MSQPCR) analysis

“…Indoor dampness and mold in children's bedrooms were important risk factors associated with allergic symptoms in young children in Singapore [4]. Also, mold sensitization was signifi cantly more common in children whose Singapore homes lacked air conditioning [5]. The objective of this study was to assess the mold growth in Singapore shopping centers using a DNA-based method of mold analysis called mold-specifi c quantitative PCR (MSQPCR) [6].…”