Stevens-Johnson syndrome/toxic epidermal necrolysis: initial assessment

### What you need to know A student in her late teens is started on lamotrigine for suspected epilepsy. Thirteen days later her eyes become red and itchy, and the following day she develops a sore throat, chapped lips, and widespread skin itching. She attends the emergency department, is diagnosed with a viral illness, and prescribed antihistamine. The next day she has a fever, malaise, facial rash, and oral ulceration. Within 24 hours the rash spreads to her torso and limbs and has started to blister. She is admitted to the intensive care unit of a specialist burns unit and over the next five weeks is treated for extensive skin loss with severe corneal and oral ulceration. Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) describes an acute, life threatening, mucocutaneous blistering disease resulting from epidermal and mucous membrane keratinocyte apoptosis.1 Blistering of less than 10% of body surface area (BSA) is known as Stevens-Johnson syndrome (SJS), and when greater than 30%, BSA is referred to as toxic epidermal necrolysis (TEN). SJS-TEN overlap exists when BSA involvement lies between 10% and 30%.1 Estimated incidence is five or six cases per million per year.2 In 85% of patients with SJS/TEN, the disorder is caused by a hypersensitivity reaction to a drug. Around 15% of patients have no relevant medication exposure, and in these cases Mycoplasma pneumoniae or viral infections are often the cause, especially in children. During the active phase of SJS/TEN, loss of large …