Advice please. My 7 year old came down with Fifths disease last Wednesday but is still really bad with it. He still has the rash which seems to flare up in the afternoons and has a very itchy scalp. He is exhausted and very whingey and irritable. How long should this be going on for and is there anything that can alleviate the rash discomfort? Will piriton help? Grasping at straws here. Thanks.