The University of Maryland recently published data about increased incidence of allergy in children correlating with the amount of residues of triclosan and paraben found in their urine.
Triclosan is a chemical that has been added to many personal care and medical products, including soap and toothpaste. It is added for its antimicrobial properties. Paraben is added to food, pharmaceuticals and personal care products, also for its antimicrobial properties.
Both have been previously shown to have immune-modulating properties (in addition to their antimicrobial property). In this particular study there was a strong relationship between urinary levels of these chemicals and the development of a variety of allergies: asthma, eczema and food allergy.
The unstated — but implied – recommendation is to limit childhood exposure to these chemicals