Whenever I go into water (shower, pool, lake)I get hives and welts throughout body. They can be itchy sometimes. Whats causing this&how do I stop it? Thanks

?aquagenic urticaria. kind of rare, you need to see your doctor who would refer you to a dermatologist / allergist for evaluation, meanwhile, you can take OTC antihistamines like cetirizine or Loratadine on regular basis, but remember to stop them about 5 days before you see the specialist, good luck.