My husband has raised red bumps, mostly on his back. A dr. took a biopsy, said it came back as a "bug bite". They continue to crop up. Checked for bed bugs, fleas, etc. by did not find any. Besides no one else has these bumps. Some are the size of a pencil eraser, while others are the sign of a thumb finger nail. This has been ongoing for five months and his Internal medicine doctor and the dermatologist cannot seem to give him an answer or relief. Topical creme, Clobetasol Propionate only gives relief for about 5 hrs. We have thought it could possibly be some sort of skin parasite from eating sushi. Any suggestions?