my 9 year old son was diagnosed with sand flea bites but Im not convinced that what it is. The bites start out small, like pin point red dots then get larger and slightly raised. Circular but not symetrical. It is spreading up to his buttocks and now on his elbows. He has complained of some joint pain behind his knees. No fever or any other symptoms and very little itching. He hada steroid shot yesterday and today I noticed more umps pop up.