Hello,
How are you?
Water urticaria, or aquagenic urticaria, is a rare condition in which hives develop within 1 to 15 minutes after contact with water. The hives last for 10 to 120 minutes and do not seem to be caused by histamine release like the other physical hives. Most investigators believe that this condition is actually exquisite skin sensitivity to additives in the water such as chlorine but distilled water can also cause this reaction.
Do you have itching for a longer time,say for>2hrs?As told by you that itching is only on the legs and not on the whole body even when water touches the whole body;I think that it can be a case of contact dermatitis or atopic dermatitis also.
In contact dermatitis there is a localized rash or irritation of the skin caused by contact with a foreign substance.
Pls consult a dermatologist for the exact diagnosis.
Water urticaria is diagnosed by applying tap water and distilled water to the skin and observing the reaction. Contact dermatitis can be diagnosed from your symptoms and physical examination. Blood tests and x-rays are not helpful.
Treatment of water urticaria includes epinephrine, antihistamines, or cortisone-like drugs. Itching can be controlled with cold packs or commercial topical agents that contain menthol, camphor, eucalyptus oil, aloe, antihistamines, or cortisone preparations.
ref:http://www.myonlinewellness.com/topic/physicallergy
Contact dermatitis is self limiting.
Pls get yourself examined by a dermatologist and then start with a treatment.
Do keep us posted.
I believe its called Aguamatic or Aquamatic Urticaria, and its after you have been in the water or showered, no one seems to know what causes it,put it in your search engine, or under Hives, Antihistimes help for the itch but so far it seems to take its course ,comes and goes.