I have a skin rash which I can't seem to get cured. I have seen two different Dermatologists and an Allergist. I have had the skin test for environmental and chemical substances and a skin test for foods and a blood test. I reacted to three substances n the dermatologists test and there were no reactions to the allergy test. the three substances which I reacted to are: Thimerosal,Glutaraldehyde and 1-(3-chloroally)-3,5,7-triaza-1-azoniaadamantane chloride (Quaternium 15). I have been unable to find any of the substances in any lotions, soaps, etc. that I have used. What would you suggest for me to do next? I have been dealing with this for about two years. Thank you for your help.

Answer: Have you had a biopsy performed? This is a simple procedure where the skin would be anesthetized with some lidocaine solution, and a small piece would be removed to be examined under a microscope. Oftentimes, this can tell your dermatologist whether the process is coming from within your body, or due to something you are being exposed to.

If you have already had this done, I would suggest delving into what therapies are available beyond things you have already tried. I have seen many patients with rashes that, try as we might, we just cannot "nail down". Sometimes trying a new medication or class of medication produces unexpected, beneficial results.