I feel okay, just extremely fed up and itchy trying to refrain from scratching but it's so hard! Took a fexofenadine couple of hours ago and it's done nothing, which is why I rang 111
I had something similar which started whilst I was in Philippines in Jan 2018. Mine progressed to anaphylaxis within a couple of days. Got an antihistamine out there which stopped it straight away but it's a controlled drug here.
Rash continued back here and UK doctors put me on Fexofenadine which was pretty useless. I tried all the over the counter antihistamines and settled on Ceterizine as being the most effective.
Eventually I was sent to a dermatologist and she gave me a script for Ceterizine in quite a high dose which did suppress the reaction after a few days.
By then I had started to suspect Glargine insulin because systemic rashes are a listed side effect, but the dermatologist was dismissive saying that it was unlikely to be my insulin because I didn't have localised rashes at injection sites. So I kept taking the Ceterizine all through last summer.
Around August time I managed to persuade the Endo' to switch me from Abasaglar to Levemir and most of my problems (including severe myalgia in my shoulders) have abated.
I also stopped using the Libre last autumn because of the rashes and now I'm not sure if maybe the Libre issue made me more sensitive to other things.
So a long winded way of saying try other antihistamines and see what works best for you.
I had been using glargine based insulin for 3 years before the muscle pain started and the rashes about 3 months afterwards. Thankfully it seems to have stopped now but I am still waiting for a referral to an immunology.