Hello I have gone through your question and understand your concern. There is nothing to worry about looks more like viral infection with rash. Mononucleosis is common in children of school age group with symptoms of sore throat and pinkish rash on torso. As it is a viral infection so antibiotics are not needed, unless some secondary bacterial infection accompany. The infection spreads through nasal and oral secretions, if the child is having running nose and other cold like symptoms it is always better to keep him home rather than sending school to avoid spread of virus. Washing hands and keeping hygiene is necessary for symptoms of sore throat salt water gargle, lozenges. Advil or Tylenol can be given if symptoms of fever or body pain manifest. Ample of rest, fluid and healthy diet will speed up the recovery time and rash will subside on its own. Hope your concern is answered. Thank you.