I just googled this on the Huggies site and found the following;

Q. What is the gel I have found on my baby's skin?
A. Huggies Nappies contain a super absorbent ingredient called Polyacrylate, which is mixed in with the nappy padding. This material turns liquid into gel, helping prevent nappy leakage. Occasionally this safe, gel material will seep out of the pad and onto your baby's skin. The gel material is quite safe and will not harm your baby in any way.


Q. How do I remove the gel from my baby's skin?
A. If you notice a small amount of gel like material on your baby's skin simply remove it with a baby wipe or a damp washcloth.


Hmmmmmm.........