Inclusion Criteria:  Aged 6 to 12 months of age history of physician diagnosed atopic dermatitis OR allergen sensitization OR family history of asthma or allergy  Exclusion Criteria:  Evidence of sensitization to house dust mite (SPT ≥3 mm OR sIgE (> 0.35 kU/L) Prematurity (<37 weeks) Failure to thrive Need for oxygen for more than 5 days in the neonatal period history of intubation or mechanical ventilation