This is something that actually is a pain in the Amazon, the itch mite is easy to get in the jungle. We always recommend to our tourist to wear swamp boots, long socks and before getting into a walk to put some Jhonson oil on their legs.
There is this product that you must have it in you first aid kit, Crotamiton in lotion is really good for this kind of itching and will get rid off the itch mites.