According to the CDC (Center for Disease Control) poison control has seen a drastic rise in calls related to e-cigarettes; from 1 call in September of 2010 to 215 in February of 2014 . The problem is that the liquid containing nicotine looks (and actually comes) in candy and fruit flavors. Additionally the liquid is not in childproof containers.
The CDC claims that more than half the calls relate to children under 5 ingesting the liquid.
With the popularity of e-cigs rising, the CDC predicts that the numbers of calls, and the number of children at risk, will only rise even more.