Alberto Manuel Gomes Martins, patient says before getting into the water you think it will feel really strange. But no, not at all. The fish are very nice. Sufferers from all over the world flock to this clinic at Kangal, in central Turkey, for what’s known as ichthyotherapy. These so-called doctor fish from the Euphrates river feed on the affected patches of skin. Psoriasis afflicts up to 3 percent of people around the world and is very difficult to treat.