The erythema exsudativum multiforme, or also known as ?Steven-Johnson-Syndrome?, is a rare mucocutaneous disease primarily caused by drugs, but also by some infections or other not yet defined factors. Young men are predominantly affected. The cardinal signs are swollen, bleeding, crusted lips and erosions/ ulcerations of the oral mucosa. Conjunctivitis, erythemas of the skin, fever and malaise are frequent. Treatment lies in supportive care, various immunomodulating therapies are discussed. The Mortality stays high despite all therapeutic efforts.