Effect of house dust mite avoidance measures in children with atopic dermatitis

Background House dust mite allergens are associated with atopic dermatitis (AD). Objectives The aim of our study was to verify if house dust mite allergen a voidance measures can improve the clinical manifestations of AD in children . Methods Forty-one children (mean age 3.9 years) affected by AD associated w ith high total and/or specific IgE serum levels ('extrinsic' AD) were recru ited. Clinical evaluation was performed utilizing the Severity Scoring of A D (SCORAD) index; dust was sampled from the children's beds and tested usin g an enzyme-linked immunosorbent assay. The study was planned in two parts. In the first part, a placebo-controlled trial of 2 months duration, mite a llergen avoidance measures (encasing mattresses and pillows; a weekly hot w ash of bedding; frequent vacuum cleaning of living room and bedroom; soft t oys and carpets regularly cleaned or removed; no pets allowed) were recomme nded to group A patients, but not to group B. In the second part of the stu dy, environmental avoidance measures were recommended to initial control gr oup B patients also, One year after the start of the study the amounts of m ite allergen in the home and clinical score of AD were measured in both gro ups. Results At the end of the first part of the study, significant decreases in major allergens of Dermatophagoides pteronyssinus (Der p1) and D. farinae (Der f1) load (from 393 to 94 ng m(-2)) and concentration (from 1.84 to 0.7 3 mu g g(-1) of dust) in children's beds were observed in treatment group A . At the same time, in this group the mean SCORAD index improved significan tly (from 33 to 26; P = 0.022). After 12 months, when all patients had used allergen avoidance measures, Der p1 + Der f1 load, concentration and clini cal score had improved, reaching similar values in both groups. Conclusions Simple mite allergen avoidance measures should be recommended t o families with children affected by extrinsic AD in order to control the c linical manifestations and prevent mite sensitization.