Suggest Remedy For Chicken Pox Like Spots On Buttocks And Upper Legs

my 7 year old son has chicken pox like spots on his buttocks and upper legs. he has had chicken pox before. two weeks ago he was admitted to hospital with a suspected appendicitis. However, it was then diagnosed as a virus. he has been well up until these spots have appeared. this morning we discovered a thread worm around his annus when checking out these sore spots. Help!