I Have Had A Breakout Of Small Red Bumps Sometimes

I have had a breakout of small red bumps sometimes 2 to 3 in a row or by themselves for about a year and a half. They itch like crazy and nothing stops the itch. I have seen a dermatologist and have had a skin biopsy taken that the results were a bug bite. I find it hard to believe that a bug bite can still break out 6-8 months later. I have tried many prescription creams and lotions,bath and acne shampoo. Nothing works.