My preschooler had the black spot poison ivy a few weeks ago on his leg. It was smaller than the head of a match. It was perfectly rectangular at first and I thought it was from a sharpie marker. A few days later when I couldn't scrub it off and he kept saying "ow!", the edges began to look pink. I thought maybe it was a burn from the corner of the oven?
I began to apply neosporin with a heavy duty bandaid. The area worsened overnight to the point where I thought he was allergic to neosporin (like his Dad) or it was just plain infected. The area grew to quarter sized swollen red spot. His doc gave him an antibiotic cream to clear it up (worked like a charm!) He still has a scar though.
I only learned that it was black spot poison ivy when my neighbor developed the same thing a googled her symptoms. I thought this was supposed to be rare according to one web site, but look out!!!
P.S. He also had a few small "blister" type spots on the leg and arms days after the black spot appeared, but they did not spread so I thought they were bug bites. Looking back they must have been the poison ivy too. Thank god they didn't turn black like these photos.
