red itchy bumps that comes and goes

[cogwurx]

My wife has had these red itchy bumps on her legs (shins, ankles, and thighs) for about a year now. The rash started in the early spring, got really bad during the hot summer we had but sort of subsided in the fall and winter. After numerous visits to the Dermatologist she was given various steroids and creams, with diagnosis being either contact dermatitis or eczema. None of these treatments have helped nor were they the right diagnosis. The only thing that seemed to help was a daily application of apple cider vinegar. We found this solution online and figured we'd try it since nothing else worked. The vinegar helped bring it down to where the itching was tolerable.

Fast forward to the beginning of this year. My wife got a nasty reaction to some antibiotics which caused the rash to flare up to the point it was spreading beyond her legs to other parts of her body. She was taken off the antibiotics immediately and was told by the doctor to take some benedryl. That worked! That had freed my wife of this itchy, bumpy hell that she has endured for a year. However, the rash still lingered under the skin. Recently, due to heavy heat and humidity the rash has resurfaced and flared up again. The benedryl and cortizone creams aren't working so well now.

Anyone have any ideas of what this could be and how to get rid of it?