Dermatophagoides farinae-, ovalbumin-and lactalbumin-specific IgG, IgG1, IgG4, IgA and IgM were evaluated in 161 healthy children [Group 1], 84 children with bronchial asthma and/or allergic rhinitis but without atopic dermatitis [Group 2], and 54 children with atopic dermatitis but without bronchial asthma and allergic rhinitis [Group 3]. We also studied D. farinae-, egg-white-, and milk-specific IgE of children with allergic diseases. D. farinae-specific IgG, IgG1, IgG4 and IgA in Groups 2 and 3 increased until 5 years of age and thereafter they remained constant. After 2 years of age, D. farinae-specific IgG, IgG1, IgG4 and IgA in Group 2 were higher than those in Groups 1 and 3. Ovalbumin- and lactalbumin-specific IgG, FgG1, IgG4 and IgA in Groups 2 and 3 increased until 1 year of age and thereafter decreased. Until 1 year of age, ovalbumin- and lactalbumin-specific IgG, IgG1, and IgG4 in Groups 3 were higher than those in Groups 1 and 2. D. farinae-, ovalbumin- and lactalbumin-specilic IgM were constant in all ages of all groups. These results suggest that atopic dermatitis in young children is related to food-specific immunoglobulins and that respiratory allergic diseases in older children is related to D. farinae-specific immunoglobulins.