Rubbing alcohol.....it helps dry it, cools it AND helps the itch temporarily.
Also......there is an herb called QUERCITIN. I took it when I had a HORRIBLE case of poison ivy several years ago. It's for allergies and asthma. WITHOUT ?, when I took this.......I didn't itch! Therefore, it didn't spread. It was AWESOME. If it said take every 4 hours, I knew EXACTLY when it began to wear off because at about 4 hours, I'd start to itch a bit.
I WOULD HOWEVER, MAKE SURE AND CHECK AND SEE IF KIDS SHOULD BE ABLE TO TAKE IT. Call a local health food store and talk to someone there.