Allergies     As a very small boy, before my memory begins, I was prone to skin complaints and other reactions. Given the allergy test, where a doctor paints   the essence of various substances over a series of scratches down one’s back, I turned out to be sensitive to almost everything, from haystacks   and pollens to house-dust, mould, eggs, milk, and animal products such as cat, dog and horse hair. The specialist told my parents that   they would need to rid their home of all these things. My father smiled. “Wouldn’t it be easier,” he asked, like…