What Causes Recurring Itchy Rash On Trunk And Limbs?

my 3 1/2 y/o granddaughter has a recurring rash on her torso and limbs. it is lacy and some of it if slightly raised. a week before this started she had what appeared to be a bug bite that had about an 1 &1/2 red bump around it. It cleared up after 2 days. then few days later this rash appeared. her dr thinks it could be Fifth s disease but I don t as she doesn t get the red cheeks. Blood work has yet to come back. She says it hurts. Dr pulled her from antibiotics when it partial cleared and then returned worse 3 days later and blood work ordered. She is taking liquid Benadyl only.