Association between indoor fungi in Delhi homes and sensitization in children with respiratory allergy

Indoor fungi are potential sensitizing agents in children and their detection and quantification in indoor air are important in the diagnosis and environmental management of fungal allergies. The objective of this investigation was to assess the prevalence of fungal allergies in children in Delhi and to study the association between mold counts in the homes of children and their sensitization to respective fungal extracts. Fungal concentrations and seasonality were studied at two-week intervals for one year using Andersen Volumetric and Burkard Slide samplers. Sensitization to fungi frequently encountered in patients' homes was assessed by Skin Prick Tests (SPTs). Total fungal specific IgE was measured by ELISA in the sera of patients positive to fungal extracts. Skin Prick Tests revealed that 39.3% (33/84) of patients were markedly positive (2 + and above) to one or the other fungal allergens. Raised serum IgE to predominant indoor fungal species was observed in patients with marked SPT results. Highest marked skin reactivity (2 + and above) was obtained with Alternaria alternata allergens in 17.9% of the children, which was followed by the response to fungal antigens of Aspergillus fumigatus and Penicillium citrinum (15.5%). Exposure to high fungal counts of some dominant fungi (Penicillium, A. nidulans and A. fumigatus) was found associated with increased fungal sensitization in the patients. Total serum IgE level was revealed to be significantly linked with the intensity of skin reactions, as well as with skin index (r(2) = 0.052; P < 0.05). We concluded that children in Delhi are exposed to high concentrations of fungi in the indoor environment and that respiratory allergies were connected with higher prevalence of skin sensitization.