Mite allergen (Der p 1) levels in houses of children with atopic dermatitis: the relationship with allergometric tests

Several studies, in particular in adult groups, have evaluated the involvem ent of mites in the pathogenesis of atopic dermatitis (AD). This still rema ins controversial. The objective of this study was to determine the level o f house dust mites (HDMs) in the beds of a group of children with AD and co rrelate these levels with their allergometric assessment. Forty-one childre n with AD underwent allergometric tests (prick test, patch test and radioal lergosorbent test, RAST) and the concentration levels of HDMs in their home s were evaluated. Our data show that about half of the children (51%) with AD presented Dermatophagoides pteronyssinus positivity (prick test and/or R AST and/or patch test). Dust was collected in the period October-November f rom the children's beds, by the same two operators, using a dust-collection device. The dust mite level was tested by an enzyme-linked immunosorbent a ssay with antibody against Der p 1 allergen, Ten children (24%) presented a Der p 1 concentration >2 mu g/g of dust (the value assumed to be a risk le vel for sensitization), 20 (49%) between 0.1 and 2 mu g/g and 11 (27%) <0.1 mu g/g of dust, In the group with the highest Der p 1 concentration (>2 mu g/g dust) nine children (90%) presented an allergometric D. pteronyssinus sensitivity, the difference with the other two groups being statistically s ignificant at P < 0.018. The results of the present study show that the hig hest HDM concentrations were observed in the group with an allergometric D, pteronyssinus positivity (prick test and/or RAST and/or patch test), It is hypothesized that a higher HDM concentration may elicit D, pteronyssinus I gE sensitization and delayed hypersensitivity in children with AD.