Let’s just see how your skin is progressing. Melissa Mok’s skin still bears a few faint scars from her ordeal a year ago. The 32-year-old went from healthy to the intensive care unit after developing a mild form of toxic epidermal necrolysis syndrome, or TENS. I had blisters all over, all over my face, eyelids, my ears, everywhere all the way down to the bottom of my feet. Dr. Neil Shear is head of dermatology at Sunnybrook, and describes TENS as a severe and life threatening disease. What it involves is your skin basically is burning off your body from the inside out and it’s horribly painful. He says about 1 in 5 people will die from it, and 4 out of 5 people will suffer the rest of their lives from having had it. And what could cause this horrible thing? Well actually, in about 7 out of 10 cases we do find the cause and it’s usually one of a few well-known drugs that can do this. Those drugs include carbamezapine used for pain disorders and epilepsy, as well as allopurinol, used for gout. TENS typically develops within the first month of therapy. If you have been newly prescribed one of these drugs, Dr. Shear says you should ask for a simple genetic blood test first. That will tell you if you’re susceptible to TENS. That applies to anyone prescribed allopurinol. For carbamezepine, that includes anyone with origins from southeast asia. Dr. Shear says right now, not enough people know about this test. If you had the gene that causes the problem, then you could have a really specific discussion about what are the alternatives. If there is no alternative than you have to pay close attention. Not everybody who has the gene is going to get the reaction, but everybody who has the reaction has the gene. Melissa says the genetic test is something she supports to ensure no one suffers the way she did. It could happen, it just could happen even though it’s really really rare. If anyone is taking any of those common medications, it’s, you know, good to know. Sunnybrook is now a leading centre for treating TENS, and Dr. Shear is a leading advocate in supporting the genetic test, and more awareness about it. With Sunnyview, I’m Monica Matys.