My Brothers Hands Are Burning, Stinging And Are Beet Red.

My brothers hands are burning, stinging and are beet red. Very painful to the point of tears. He believes this started after washing walls that had many years of cigarette smoke buildup. In addition to that Raid insecticide spray was on the walls and also an insecticide bomb was activated. This happened approx. 2 years ago and he has experienced these symptoms this entire time. He is currently taking 800 mg. of neurotin 3 times daily with mediocure results. The burning and stinging persists but is tolerable. Any help you could advise will be appreicated. Thank you in advance.