It almost sounds like scabies to me.. They burrow under the skin and leave track marks or tunnels. We take in foster kids for the state whenever they require a home for a child in emergency situations and one time last year we were called to take 2 little boys ages 1 and 3. We met CPS and the kids at the hospital where they were being looked at and treated for acabies. The nurses showered them with medicated body wash and they were kep for 3 days for dehydration and sent home with a bottle of medicated wash. Theit parents were junkies and were living in a tent. Their dad just got out of rehab and blamed that as the source... But by the time the kids were released from the hospital, they had found a grandparent that was suitable to care for them... But i will never forget that sight... Little kids with purple/grey lines on their skin. I am new to all this so someone else can tell you better... But i believe theres a drug called ivermectin or something that can be purchased at pet or farm supply stores that will treat that. As for the worms, i am very new as well. We just found out 2 weeks ago our 8 year old had pinworms. No one else in the family had symptoms but were treated with albenza and have since passed what appears to be pinworms in the toilet. We are only 2 weeks in to this so i cant say from experience what is the most effective, but start by investing in a steam mop and steam everything and wipe everything down with straight clorox. Search for ICU's protocol on here... Drugs and dosing info. Lots of luck! you're in for the fight of your life! These bastards are tough to get rid of!