Key Takeaways If you get a rash while taking Lamictal, you should see your doctor right away. Lamictal can cause serious reactions like Stevens-Johnson syndrome or toxic epidermal necrolysis. To avoid a serious Lamictal rash, start on a low dose and increase it slowly. Lamictal rash is a side effect of the prescription medication. This guide discusses symptoms of the rash, as well as information about treatment and diagnosis. If you get any new rash while taking lamotrigine, call your prescriber the same day, even if the rash looks minor. Go to the emergency room right away if the rash blisters or peels, spreads quickly, or comes with a fever, mouth sores, or eye pain. Lamotrigine can cause a rash, which may range from mild to serious. Learn how to identify symptoms, reduce risks, and when to seek medical help. Learn how to spot a mild lamotrigine rash versus a serious reaction, and know when to call your doctor right away. Most Lamictal rashes are harmless, but some signal a serious reaction. Learn how to tell the difference and when to call your doctor. Stop lamotrigine immediately at the first sign of any rash—this is the single most critical action to prevent progression to life-threatening Stevens-Johnson syndrome or toxic epidermal necrolysis. 1 Key Takeaways Lamictal can cause a rash that may be a sign of a serious allergic reaction. The rash can appear as small, itchy, pink bumps on the skin. If you notice a rash while taking Lamictal, seek medical help immediately, even if the symptoms are mild. In this article, we cover the frequency of Lamictal rash, symptoms, treatment, and possible complications. One side effect of taking lamotrigine (Lamictal) is a rash, which may turn serious. Learn how to recognize it, treat it, and when to get emergency help.