Itching after swiming

[Zack_s_Dad]

A few hours after swimming, my son starts itchinb very bad -- mostly on his legs. He scratches to the point of drawing blood. We have been treating this with benedryl. The last episode was so bad we took him to the emergency room for a shot.

He has been in four pools and has itched in two of the four. Of the two pools he had trouble with, one was a salt-water pool and the other wasn't. Both the pools he was okay with were salt-water.

We have tried to eliminate everything we can think of: it's not his suntan lotion -- he has worn it without going in the pool and he is fine. It's not his his swimsuit -- he has worn it while playing with the hose and had no problems.

We took him to an alergy specialist. He said the ***** test was for immediate reactions and the patch test was for latent reactions. Since he reacts hours after getting out of the pool, he choose the patch test. The only alergy the patch test showed was to the tape used to hold the patches on his back.

Any ideas? Could there be some type of tree or plant [adjacent to two of the pools and not the other two] whose pollen has gotten in the pools?

[Zack_s_Dad]

Why would he have trouble in two pools but not in the other two pools? The chlorine levels in all four pools seemed to be about the same.

In fact, the last pool he was in had free and total readings around .5 -- which is actually low.

Thanks.

[Dr_Aparna]

Hi,
The chlorine in the water used as ableaching agent maybe the cause.Or it could be the water itself.
Water urticaria, also known as aquagenic urticaria and aquagenous urticaria, is an extremely rare form of physical urticaria. It is sometimes described as an allergy. In affected persons, water on the skin causes hives to appear within 15 minutes and last for up to two hours.
Urticaria (or hives) is a skin condition, commonly caused by an allergic reaction, that is characterized by raised red skin wheals (welts). Wheals from urticaria can appear anywhere on the body, including the face, lips, tongue, throat, and ears.
Drug treatment is typically in the form of Antihistamines such as diphenhydramine, hydroxyzine, cetirizine.
ref:http://en.wikipedia.org/wiki/Physical_urticaria