<s>[INST] My 14 year old son woke up with a red rash on his chest and side. Then it developed on the inside of his arms and later his elbows. The rash itched and burned when the sun would hit it. The next day it was mostly gown but what remained looked like a 5 day old bruise. Each day the rash developed on different parts of his body and go way leaving a bruising spot. The ER doctor had no idea what it could be. [/INST] Hello, If he is not having any fever then it can be scabies. Scabies is very contagious. Wash all the clothes in Salon or Detail & do not share or use his clothes. Apply lotion Scabies (Benzyl Benzoate) after a bath, leave it for 30-40 minutes & let him take a shower after that. The spread of the infection should get controlled. You can give him antihistamines or Ben Chat Doctor.  Hope I have answered your query. Let me know if I can assist you further.   </s>