My sister is 12 years old and has a rash that started on the back of her upper arms and has been spreading across her whole body for 5 days now she had a fever to start with, but that has since gone away. the rash is preceded by itching every where it has spread and on the 5th day (today) it has spread all the way to her knees. the rash looks splotchy, as if she got a sun burn while wearing a very loose knit shawl, but the rash is raised and is the color of a faint new sun burn. Our doctor doesn't know what it is and her blood work is all normal except for a just below normal iron level. we have tried anti-hystemines, but to no avail.
please help!