Is it just itching or you have also blisters like a mosquito bites?if so, it is urticaria, idiopatic skin reaction (kind of allergy), not uncommon in BFS cohort and triggered by either heat, or sweat, or even by water. it also could be triggered by anxiety episodes, food or wear. But mostly it is a reaction caused by heat/cold, sweating and watering. Our fat cells suddenly release huge amounts of acethylcholine triggering blistering, itch and redness.hope this helps. I have urticaria for several years already, and some fellows reported it too.