Molly is a ten year old girl who presents to A&E with a three day history of rash which started on her torso and then spread to her arms and legs. During this time her mother reports Molly has also had some coryzal symptoms and intermittent temperatures.
On examination Molly has a widespread maculopapular rash which has a coarse texture that is more pronounced over her skin folds. She has a fever of 38.2 and her throat is erythematous. The remainder of her systems examination is unremarkable. She has no known drug allergies.
Given the most likely diagnosis what is the most appropriate next step?