This rash is different from urticaria as it can persist for weeks. It is usually very itchy. It appears as red and bumpy areas which may occur anywhere on the body, such as the elbows and knees as well as the back of the hands and feet. It can resemble bad prickly heat. In some cases, it is only tiny bumps all over the skin and the signs may be more subtle. The rash can also last well after the contagious stage is over and may also appear many weeks after the onset of the infection.