Editor's note: This is a guest column by Kristin Hardy, who was diagnosed with primary progressive multiple sclerosis in 2002. Her sister Margaret was diagnosed the same year with relapsing-remitting MS, complicated by trigeminal neuralgia. You are invited to follow Kristin’s blog at www.hackmyms.com. *** It started out with mosquito bites — three of them — high up on my sister’s thigh. At the time, we didn’t think much about it. It was a weird spot, but in New Hampshire, late-season mosquitoes are persistent little buggers. Margaret just scratched and bought a tube of After Bite at the pharmacy, where she’d gone to pick up antacids. The next day, it was cream for a yeast infection. A day or two after that, she had a sore throat, then a rash, then a fever spiking so quickly that in the amount of time it took to shake down the thermometer from one reading to the next, her temperature rose half a degree. By then, we knew the red spots weren’t mosquito bites, they were hives. It would be another three days before we had an official diagnosis that tied together all of her symptoms: Stevens-Johnson syndrome (SJS), a skin and mucous-membrane disorder with a significant mortality rate. Think of that line from the drug commercials that usually follows the rapid-fire listing of side effects: "Call your doctor immediately if [insert phrase here], as this may be a sign of a rare but serious side effect." For therapies as varied as carbamazepine, Naprosyn, and even ibuprofen and acetaminophen, the U.S. Food and Drug Administration doesn’t mince words: The reaction is characterized as not just serious, but sometimes fatal. And its name is SJS. Want to learn more about the latest research in MS? Ask your questions in our research forum. Stevens-Johnson syndrome is not a drug allergy. It is a chemical reaction that takes place in the cells of the skin and mucous membranes such as the mouth, ears, nose, eyes, lungs, G.I. tract, and genitals. Basically, exposure to some agent causes the immune system to go haywire and begin releasing signaling chemicals that trigger cell death. A red or purple rash springs up that forms blisters that burst and then peel. This is the danger with SJS: As the spots grow together, large swaths of skin can be stripped away, leaving the sufferer vulnerable to infection. SJS requires immediate hospitalization, frequently in the ICU or burn unit. Treating SJS In the case of my sister Margaret, who was visiting me, the expertise at my small-town hospital was just good enough to identify the syndrome. Fortunately, we live an hour away from Boston. We were able to get her transferred to Brigham and Women’s Hospital, a facility listed on the U.S. News & World Report Honor Roll of top U.S. hospitals. No sooner had she been admitted than — like somebody in an Edward Jones commercial — she had people around her, including a dermatology team, an ophthalmology team, a gynecology team, and a general medicine team. They put tissue grafts in her eyes to protect her vision, as the eyelids are lined by mucous membranes and affected by SJS as well. They can form blisters that during the healing process can grow onto the cornea, leading to vision damage or even blindness. In Margaret’s case, the grafts prevented this issue. In fact, she was pronounced by the doctors to have a mild case. Then again, it’s difficult to even think about using that word about a person who spends nearly a month in the hospital in agonizing pain while her body wars with itself. For Margaret, the culprit appeared to be carbamazepine, a treatment her neurologist had recently prescribed for pain caused by her trigeminal neuralgia. For years, she has practiced self-hypnosis for pain control, resorting to medications only in her most agonizing moments. Now, that has been taken from her. She can’t ever take any medication from that family again. Know the symptoms You’re reading this story because we both feel that it is important to educate the MS community on SJS. It’s a very rare disorder, and you’re more likely to be struck by lightning than to contract it. For carbamazepine users, however, SJS is far more common. FDA labeling estimates that as many as six of every 10,000 new users will experience SJS. And carbamazepine is the go-to medication for treating trigeminal neuralgia. None of this is to suggest that you quit or avoid taking carbamazepine. Just educate yourself. Speed of response has an enormous effect on prognosis. Talk to your doctor and make sure you know the symptoms. Be aware that the disorder can occur at any time, whether on your first dose of a new medication or your hundredth. And most of all, educate those around you so that if anyone begins to contract SJS, they get to a hospital as quickly as possible. Over a year has passed since Margaret’s illness. While not entirely recovered, she is past the worst of it, and it appears she won’t have significant lasting effects. One thing is certain, though: We will never look at a simple mosquito bite the same way again. *** Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The opinions expressed in this column are not those of Multiple Sclerosis News Today or its parent company, BioNews Services, and are intended to spark discussion about issues pertaining to multiple sclerosis.