What are the ramifications of a child ingesting Advantage flea/tick medication?

Awhile back my son who then was about 18 months got his hands on a tube of Advantage and ingested it. (Yes, I know it was irresponsible of me to leave one way back on the counter when I was using another on my cat.) Afterwards, I called Poison Control which informed me it was not toxic enough to cause any harm. However, I recently heard a report about some of these meds causing negative side-effects like severe skin irritation and neurological disorders on pets. Does anyone have more recent information? Is it still believed to not cause problems?