Suggest Remedy For Itching

I have been suffering from itching for close to 6 months now. It started on my back with no apparent reason. I would have family inspect my back constatly looking for a cause and nothing. About a month ago my itch has progressed to all over my torso and in the past week all over my body. Cause still unknown. I've tryed serveral topical lotions for itching and would do very little if anything. I am getting worried that it may be somthing serious going on in my body and this itching is just a side issue. Please help.