I have recently learned from Tony Pearson that you recently had GBS. It would be quite unusual to have sensory symptoms of this kind in the back as a result of GBS. They can certainly occur in the limbs and I guess it is possible that they could also occur elsewhere. The “buzzing” symptoms can occur following GBS and probably are related to the nerves recovering so are a good sign. If the symptoms are from the GBS, topical lotions will not help. If the symptoms are distressing medication such as nortriptyline, gabapentin or pregabalin can help so you should talk to your doctor about that possibility.