Hi All, I'm back, cos the itch is. Eight months clear (the hottest eight months in our part of the world), and suddenly 24 hours ago I get itchy. Not severe this time (touch wood), and back and shoulders rather than chest. I know it's the old G from the sensations. A particular, persistent kind of itch, and very strong sensations followed by relief from a VERY hot shower.
TomA, I checked the band-aid thing and it doesn't cause me a problem. Nor does seawater, which somebody else finds to be a trigger. No seatbelt pattern. No visible correlation with physical vs. sedentary work. My diet, lifestyle, etc.: no change recently.
As several of us have said, it seems to be different for all of us, both triggers and treatments.
Last time I had it, it stayed with me from a cool temperate region in winter, to the tropics, and back again. Lasted about four months, most severe at the beginning. I haven't got a ghost of a clue so far what my trigger/s is/are. I'll get back to the Vitamin D supplementation, because I just suspect that may have helped, and I do think that coconut oil was very soothing and perhaps alleviated symptoms a bit over time. Short-term, a fiercely hot shower reliably gives me a few hours' relief, and nothing else does. For me, the whole thing seems to come and go at random. Part of the last eight months, I was eating less grains and more animal protein, because my partner was trying Paleo for migraines (Paleo didn't fix them, but we did confirm her sensitivity to wheat and dairy, which we had already suspected). For me, part-Paleo/non-Paleo made no difference, and I know my body appreciates a hunk of wholemeal home-made bread and local cheese from time to time. [Dear Paleo missionaries: I'm glad it works for you. It didn't for me. Thanks for sharing.]
I just have to come back to the conclusion that Grovers is a very individual thing.