To the Editor: While it is interesting to note that Beyan et al. have found yet another variable that correlates (albeit negatively) with the incidence of Type 1 diabetes, I think it is a mistake to confuse the hygiene hypothesis with "personal hygiene" as judged by the use of deodorants, aftershave, etc. The hygiene hypothesis is based on the concept that early exposure to infectious agents is important for education of the immune system, and I am not aware that airborne infection (or for that matter infestation with Enterobius) is related in any way to the number of personal care items in a shopping basket.