My daughter was in Michigan for 3 days playing in a lake and tubing and things of that nature. She returned home to Colorado, and about 24 hours later began developing a splotchy deep red mark on her upper arm. It started out about 3 inches long and 2 inches wide. In the past day and a half it has almost doubled My daughter was in Michigan for 3 days playing in a lake and tubing and things of that nature. She returned home to Colorado, and about 24 hours later began developing a splotchy deep red mark on her upper arm. It started out about 3 inches long and 2 inches wide. In the past day and a half it has almost doubled in size and changed to a lighter splotchier red. It continues to get worse. She had her finger poked, and her red blood cells looked good, and was checked for ticks but none were found. They also checked her lymph nodes for leukemia but she was fine in that respect. Just looking for some more ideas of what it might be. It is not painful to the touch, and she seems as energetic and happy as ever.in size and changed to a lighter splotchier red. It continues to get worse. She had her finger poked, and her red blood cells looked good, and was checked for ticks but none were found. They also checked her lymph nodes for leukemia but she was fine in that respect. Just looking for some more ideas of what it might be. It is not painful to the touch, and she seems as energetic and happy as ever.