Maternal hookworm was associated with reduced eczema incidence [ adjusted hazard ratio ( 95 % confidence interval ) , p-value : 0.71 ( 0.51-0 .99 ) , 0.04 ] and modified effects of known risk factors for eczema : Dermatophagoides-specific IgE in children was positively associated with eczema incidence if the mother had no hookworm [ 2.72 ( 1.11-6 .63 ) , 0.03 ] , but not if the mother had hookworm [ 0.41 ( 0.10-1 .69 ) , 0.22 ] , interaction p-value = 0.03 .