The rash caused by Stevens-Johnson syndrome is a purple or red rash that comes on quickly and spreads within hours or days, notes Mayo Clinic. The syndrome may also cause blisters to form on the skin and on the mucous membranes found on the genitals, eyes, nose and mouth. It can also cause hives to develop on the body, and the skin can feel painful.
In addition, Stevens-Johnson syndrome may cause the facial area to swell, notes Mayo Clinic. The skin may also shed as a result of the condition.
Prior to the characteristic rash of Stevens-Johnson syndrome setting in, other symptoms may be experienced. In the few days leading up to the rash developing, fever, fatigue, burning eyes and cough may be experienced. The person sometimes experiences a sore throat and mouth before the rash's onset.
Stevens-Johnson syndrome is a serious condition that requires immediate evaluation by a medical professional. Some symptoms of the condition to watch for that indicate the need for immediate medical help include tongue swelling, spreading rash, shedding skin and unexplained widespread skin pain.
The condition, which is unpredictable and rare, is sometimes caused by medications, such as penicillin or ibuprofen, or it may be caused by infection, including hepatitis and pneumonia, among others.