Does a 'reverse' atopic march exist?
The classical description of the atopic march usually refers to the progression from atopic dermatitis towards asthma, but this pathway has been questioned. We assessed in a prospective observation the possible onset of atopic dermatitis in children with asthma alone at baseline, and evaluated retrospectively their characteristics. Seven hundred and forty-five children (360 male, 6-9 years of age) with asthma alone, without food allergy or atopic dermatitis, were followed-up with regular visits for 9 years. 692 children completed the 9-year observation, and 20% of them were found to have developed atopic dermatitis at 9 years. Comparing retrospectively the children who developed AD with the remaining, no significant difference existed at baseline concerning the demographic characteristics and family history. There was a significantly higher proportion ( chi2 = 0.01) of subjects with single sensitization to mites and a significantly lower proportion of polysensitized subjects ( chi2 = 0.01) within the children who developed AD. Sensitization to foods appeared in 9% of children who developed AD and in 3.8% in the other children (NS). According to these observations, the development of a particular allergic disease does not necessarily follow the classical paradigm of the atopic march.