Abstract
The prevalence of serum IgE antibodies to Dermatophagoides pteronyssinus (house-dust mite), Aspergillus fumigatus, and bovine beta-lactoglobulin was significantly greater in cases of sudden infancy death (S.I.D.) than in a control group of infants of the same age range. This difference was most pronounced with D. pteronyssinus antibodies, which suggests that hypersensitivity to house-dust mite may be a factor in the aetiology of S.I.D. in Western Australia. Both the S.I.D. and control infants had similar serum concentrations of immunoglobulins G, M, and E but IgA levels were significantly higher in the control group.