Early-life domestic aeroallergen exposure and IgE sensitization at age 4 years

Cat ownership is a risk factor for the development of anti-cat IgE but not current wheeze at age 5 years in an inner-city cohort

“…Although many prospective studies have reported an inverse association between cats in the home and the development of sensitization, [11][12][13]27 a positive association between cat allergen and sensitization was reported recently in 2 European prospective studies. Both found a nonlinear increase in the risk for sensitization to cat with Fel d 1 exposure at birth 7,8 but no association between pet ownership and sensitization. The authors point to a relatively lower community prevalence of cat ownership as possibly leading to the difference in their findings.…”

“…The mean levels of domestic Fel d 1 among cat owners in communities with low cat ownership (eg, NYC, Germany, and Kuwait) have been less than levels of Fel d 1 in cat owners' homes in communities where cat ownership was more common (eg, Virginia, Sweden, and New Zealand). 15,26,27 In the recent European studies in which an increased risk for sensitization with Fel d 1 exposure was observed, few of the homes had Fel d 1 levels as high (>20 μg/g) as the protected group from the study by Platts-Mills et al 7,8 Nonlinear trends of increased risk for sensitization with cat allergen exposure in Germany and NYC (ie, decreasing with the highest exposure; see footnote in Table II) could lend support to this theory but have not been adequately evaluated in these studies because of the low number of highly exposed children. 8 The reason for lower cat allergen levels in the dust of homes with cats in different communities is not clear but could be due to housing characteristics or pet-keeping habits.…”

Original Article. Sensitization to Aeroallergens in Pediatric Patients with Allergic Rhinitis and Asthma

“…This sensitization correlates well with indoor allergen exposure in young and school-age children [20][21][22][23]. It has been found that adults in the US spend an average 87% of their time indoors [24].…”

Arthropod Allergens in Urban Homes

“…All this suggests that infancy may be a critical time for exposure to common indoor allergens and later development of asthma. However, although the relationship between allergen exposure and asthma is widely accepted, several recent studies challenge this dose-response concept (67)(68)(69)(70) is associated with higher production of specifi c IgG4 antibody and decreased cat-specifi c IgE response, which could result in better protection against sensitisation (62,71,72). This induction of tolerance to Fel d 1 could actually reduce the risk of allergy development (11,18,71) In addition to mite, cockroach, and pet allergens, mould and pollen allergens, viral infections, and especially tobacco smoke may contribute to the development of sensitisation and respiratory diseases (2,10,73).…”