Staphylococcus aureus sensitization and allergic disease in early childhood: population-based birth cohort study.

BACKGROUND: Staphylococcus aureus-secreted enterotoxins (SEs) may be involved in the pathophysiology of atopic diseases.
OBJECTIVE: We investigated the role of SEs in allergic diseases during early childhood (using the mixture of SE-specific IgEs [SE-mix] as a marker).
METHODS: Children (N = 510) were followed from birth to age 5 years (repeated questionnaires, IgE to inhalant and food allergens, lung function [spirometry, plethysmography], airway reactivity [dry air challenge]). We measured SE-mix specific IgE (SE-A, SE-C, toxic shock syndrome toxin 1) by using fluorescence immunoassay.
RESULTS: We found no association between rhinitis and SE-mix sensitization. Children with eczema were more frequently SE-mix-sensitized than children without (17.4% vs 8.3%; P = .02). SE-mix sensitization rate increased significantly with increasing eczema severity (no eczema, mild, moderate/severe: 8.3%, 14.8%, 42.9%; P = .003) and remained independently associated with eczema in a multivariate model adjusting for total IgE (adjusted odds ratio, 2.19; 95% CI, 1.05-4.56; P = .04). SE-mix sensitization was associated with current wheeze in the univariate but not the multivariate model. Among wheeze phenotypes, persistent wheezers were most commonly sensitized to SE-mix (never, transient, late-onset, persistent: 8.5%, 3.8%, 7.7%, 17.6%; P = .05). Among wheezers, those SE-mix-sensitized had significantly higher airway reactivity compared with those nonsensitized (mean FEV(1) change, mL [95% CI]: -59 [-121, 3] vs 19 [-10.2, 48.9]; P = .04), with little difference after adjusting for atopy.
CONCLUSION: We found differences in SE-mix IgE antibodies between healthy 5-year-old children and children with eczema and wheeze. The proportion of patients sensitized to SE-mix increases with increasing disease severity. CLINICAL IMPLICATIONS: Staphylococcal enterotoxins are potential modifiers of childhood wheeze and eczema.