What is stephen johnsons syndrome?

SJS. A very serious skin reaction with very high morbidity and poor prognosis. Drugs are the most common cause, but viral infections (including hiv) have also been implicated. If there is even the slightest concern for sjs, you need to seek immediate dermatologic evaluation as this is a medical emergency. This is in the same family as erythema multiforme and toxic epidermal necrolysis.
Severe reaction. A very serious(rare) problem usually due to an infection or medication. Includes dramatic red/purplish rash with fever and swelling. A medical emergency.