Stevens-Johnson syndrome is a rare but serious condition that causes sores that are like blisters on the mucous membranes of the mouth, nose, genitals, and eyes. A widespread skin rash of irregularly shaped, flat, red spots also develops, which may be painful and peel off.

The skin rash may develop on any part of the body but often begins on the face and chest (trunk). Sores that develop on the mucous membranes weep a thick grey-yellow fluid. When these sores occur on the inside of the eyes, the fluid hardens into a crust. When sores occur in the mouth, eating and drinking can be painful.

Stevens-Johnson syndrome is usually caused by a reaction to a medicine. The condition may result from an infection. In some people, the cause is unknown.

Even mild Stevens-Johnson syndrome can get worse quickly and become serious, so it's treated in the hospital. You may receive nutrition and fluids through a tube into the stomach or intestines. Liquid nutrients may also be delivered into the bloodstream through a needle or catheter that is inserted into a vein (intravenous feeding). A doctor will treat mouth and eye sores. In some cases, skin grafts are needed.

Recovery from Stevens-Johnson syndrome may be slow. It may take weeks or months to get better based on how bad the condition is.