I got the same problem but now improve a lot. Methods:
1. Dr Lo said 濕疹 is due to our skin very dry, so don't have hot shower. (I love very hot water for my shower!!!). Use maid temperature only.
2. Dr. Lo advise no more than one shower a day if your tummy is itchy. Otherwise, skin will become very dry.
3. I use QV shower gel ... that is quite good for sensitive skin.
4. Another doctor, Dr. Cheung (Jordon) give me some cream for the itchy area (like mosiquto bike, a little pit pink). Dr. Cheung said that was caused by hormones.
5. Lastly, apply oil/ cream after you wash yourself.
My problem get a lot better now. Hope above helps! :>