Hello, My 25 Son Complained Of Having A Flu About

Hello, my 25 son complained of having a flu about 5 days ago. He presented with fatigue, severe headaches and insomnia. Lack of sleep made him even more tired and could not go to work. He started to develop a rash which was mild at the beginning but appears to have spread all over his body. He complained of it being very itchy. He sent a picture of it and I got really worried. It looks very much like measles. I asked him to go to the nearest urgent care immediately to have it checked. What do you think this could be?