leopard gecko with swollen tail and cut/sore on its tail

Question
so i got 2 new leopard geckos from a friend about ten days ago. one is fine, but i noticed that one of them had a tail slightly more swollen than my other leopard geckos' (enoough that the usual ring ridges things weren't visible).

i left for christmas last week (about 3 days after getting them) and apparently the swelling has gotten much much worse as well as a cut has formed on its tail, which has in the past day or so opened into a sore. to make things worse she shed and it is sticking to her (that might be why the cut got worse? or possibly from the swelling?)

so my poor friend who is looking after her is at her wits end, and i'm pretty worried as well, especially since i'm not gonna get back in town until the second of january to deal with this.
i'll probably be wiring money for my friend to take her to the vet but as it is christmas it'll be a few days before i can do that.

when i got her although her tail was slightly swollen, she didn't seem to have a cut on it at all, so she's getting worse pretty rapidly. hm, also it might help to tell you that she's an adult, but just barely i think (she still has the faintest touches of stripe left on her back) and they were feeding her mealworms before, although i have been feeding her crickets.

i was hoping you might have some insight or advice on home treatment or something in the interim? even a likely cause would be good.

please help, i'm pretty freaked out here!
thanks so much

Answer
Hello Ana,

Oh, that is too bad.   

Do you have a picture of that possibly?  
The initial cause could be an injury from a tank mate, or retained shed, or a cricket bite.  
Were any crickets left in the tank with them overnight at all?  
It could be from retained shed, yes.  Do you have a moist humid hide for them to use to help with shedding?
What are the temperatures in the tank currently?  
What type of substrate is she on, sand, tiles, paper towels?  If she is on loose substrate remove that substrate & replace it with paper towels to help keep the area clean.  
You can try to bathe her if possible.  Use some antibiotic ointment on that area several times a day to help ward off infection.  

Let me know how she is doing.
Tracie