My wife had cushings syndrome, which was treated with an operation to the pituitary gland. Post operation she developed diabetes insipidus. As a result of this condition, she was prescribed to use dexamethasone spray which she uses daily. Although this spray balanced her water intake/urination, she finds it very hard to sweat even after hard exercise.
This brings the question of her having anhidrosis to our minds. However, since she doesn't have any symptoms of dehydration, why would this condition occur?