It's hard to say for sure. The people I talked to when I was worrying said the rash can be anywhere. One person said she had a rash on her leg, another person had rash on just one half of his body, another person had rash on both legs and buttocks. The rash apparently doesn't last very long, based on what other people have experienced with ARS rash, it lasts a few days. The ARS is also said to not be itchy or painful, just a red macular, usually on the chest or upper arms, but also mentioned to be on thighs or buttocks.