Hi, After reading your query it appears to be simply Pityriasis rosea. It is a viral rash which is an acute, self-limiting disease. It is a sharply defined, erythematous(reddish to pink), round or oval plaque. In general the condition remains for 2-6 weeks and then subsides by itself. So in your son it may remain for next few weeks of period an then will subside by its own. Topical steroid cream such as mometasone or fluticasone cream can be applied. Apply in very thin amount so that it should be visible to the naked eye. Additionally an antihistaminic tablet such as Loratadine can be take for 1-2 times or even up to three time if the itching is troublesome. Take care.