Hi, welcome to the forum, there are cases been reported in few posts regarding 'allergic to water' (
http://www.medhelp.org/posts/Allergy/Allergic-to-water-Aquagenic-Pruritus/show/1292538). Very less has been known about water allergy. It can be due to exposure to allergens present in water in your area or due to ions in non-distilled water.
If you are allergic to water following measures will help you-
- Stay away from water as long as possible.
- Avoid going in rain outside.
- Keep yourself cool during summer as even sweating will cause reaction.
- Try boiling water before bath and as well can try hot water bath. Avoid showers.
- Dry yourself immediately as soon you finish your bath.
If you want to enjoy the shower/water bath/ swimming then you can try anti histamines against prescription prophylactic i.e. one hour before the exposure.
I hope this will help you. Take care and regards.