First off, welcome to Reptilehaven! (RTB to me still....)
At this point, yes, a vet trip is needed as it does sound like a nasty infection that may be on the way to being systematic and will lead to the demise of the leo if not treated.
Now lets talk prevention.
Leos need at least one humid hide, usually a small tupperware container with some sphangum moss to aid in shedding.
During the shed faze, you will see the colors get dull to nearly white, this is the time to find the tweezers, to have on hand, for when the shedding is complete.
After the leo pulls its shed skin off, there may be small bits of old skin still attatched to anywhere on it, the tail, toes, nostrils, eys etc. Check evrywhere!
Use the tweezers to gently get the shed skin off of where it is to prevent constriction of the involved parts. Even the tiniest amount of retained shed can cause loss of the toes and tail.
In other areas, such as the eyes, the shed will harden and can scratch the eyes, causing blindness up to infections, which will become deadly very quickly.
Here's a pic of a leo that suffered from retained shed which caused the loss of most toes and scratched eyes.
The scratched eyes, led to the inability to hunt, therefore eat.
It was left untreated for retained shed for quite some time, allowing further damage to the eys, leading to an infection severe enough that the eyes did not exist and there was no hope for it. ( I put it down asap!)
[addsig]