Loss of appetite does often happen before a shed, especially in young Chams. You can often see skin go 'milky' just before a shed too, but not usually going loose or wrinkly.
With babies it all happens very fast so it's usually all done in a day anyway.
Thanks for quick reply, my little Rango has shed for the 1st time since Iv had him, he was eating loads yesterday nd has only eaten 3 crickets today!! U were spot on, he went completely milky today nd has now shed