Otitis-prone children and controls: a study of possible predisposing factors. 1. Heredity, family background and perinatal period.

In a retrospective study of 179 otitis-prone children and 305 controls, various possible predisposing factors for acute otitis media (AOM) were compared. The children were matched for age and sex. There were 61% boys and 39% girls in the otitis-prone group and 58% boys and 42% girls among the controls. Eighty-eight (49%) of the otitis-prone children experienced > or = 11 episodes of AOM and 162 (53%) of the controls had none or at the most one episode of AOM. There were no differences between the groups concerning dwelling districts, the size of family, number of siblings or the education and occupation of the parents. In the otitis-prone group there were more fathers who had been otitis-prone as children. This was not seen for the mothers when comparing all the children, but was seen when comparing the most otitis-prone (> or = 11 AOM) with the controls (0-1 AOM). The otitis-prone children more often had siblings who were otitis-prone compared with the controls. There were no differences between the two groups regarding pregnancy, birthweight or duration of breast-feeding. Thus, male gender and heredity for middle-ear problems appeared to be of importance for otitis-proneness.