I have pretty severe RLS, and I have found that I react to various prescription drugs and OTC. For example, benadryl is a killer for me, as are statins. Is your husband on any medications or supplements? I google everything before I take it, e.g., "benadryl restless leg syndrome" but without the quotes. Another thing I react strongly to is dehydration, so maybe pick up some Drip Drop powder or other dehydration powder and have him drink a glass or two each day to see if it helps. Best wishes for a resolution soon.