Providence Journal: At some point —- in between the interminable nights spent scratching her welts and the days of dousing them with rubbing alcohol —- Deborah Rosen walked into her Kingston backyard to investigate the poison ivy patch responsible for her misery. She`d had a few minor outbreaks over the years. But this spring`s reaction was so severe she would eventually camp outside a closed clinic on a Saturday morning waiting for a doctor`s help. What she found in her backyard surprised her …