As you said, it could very well just be something in the air... do you have allergies by any chance?
Have you changed your laundry detergent recently? Just asking as sometimes we are sensitive to such things, and it can irritate your skin and cause the itching.
It also could be a bile duct blockage, which will cause bile to be deposited in the blood stream... and this will cause the intense itching.
I think with your gall bladder history you may want to have the bile ducts investigated a little more if it the itching persists. Did you have any stones by chance? or just a low ejection rate?
Do you have any other symptoms? Fatigue maybe? Usually a bile duct blockage will present with other symptoms. A blood test can rule out the bile ducts as the problem, as well as an ultrasound or ERCP. Maybe just ask your doctor to check liver enzymes as well.
Other than allergies/irritation and the bile duct thing, I have no idea what could cause such intense itching... I hope you are feeling better