Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a severe skin reaction most often triggered by particular medications. Although Stevens-Johnson syndrome and toxic epidermal necrolysis were once thought to be separate conditions, they are now considered part of a continuum. Stevens-Johnson syndrome represents the less severe end of the disease spectrum, and toxic epidermal necrolysis represents the more severe end.

SJS/TEN often begins with a fever and flu-like symptoms. Within a few days, the skin begins to blister and peel, forming very painful raw areas called erosions that resemble a severe hot-water burn. The skin erosions usually start on the face and chest before spreading to other parts of the body. In most affected individuals, the condition also damages the mucous membranes, including the lining of the mouth and the airways, which can cause trouble with swallowing and breathing. The painful blistering can also affect the urinary tract and genitals. SJS/TEN often affects the eyes as well, causing irritation and redness of the conjunctiva, which are the mucous membranes that protect the white part of the eye and line the eyelids, and damage to the clear front covering of the eye (the cornea).

Severe damage to the skin and mucous membranes makes SJS/TEN a life-threatening disease. Because the skin normally acts as a protective barrier, extensive skin damage can lead to a dangerous loss of fluids and allow infections to develop. Serious complications can include pneumonia, overwhelming bacterial infections (sepsis), shock, multiple organ failure, and death. About 10 percent of people with Stevens-Johnson syndrome die from the disease, while the condition is fatal in up to 50 percent of those with toxic epidermal necrolysis.

Among people who survive, long-term effects of SJS/TEN can include changes in skin coloring (pigmentation), dryness of the skin and mucous membranes (xerosis), excess sweating (hyperhidrosis), hair loss (alopecia), and abnormal growth or loss of the fingernails and toenails. Other long-term problems can include impaired taste, difficulty urinating, and genital abnormalities. A small percentage of affected individuals develop chronic dryness or inflammation of the eyes, which can lead to increased sensitivity to light (photophobia) and vision impairment.

SJS/TEN is a rare disease, affecting 1 to 2 per million people each year. Stevens-Johnson syndrome (the less severe form of the condition) is more common than toxic epidermal necrolysis.

People who are HIV-positive and those with a chronic inflammatory disease called systemic lupus erythematosus are more likely to develop SJS/TEN than the general population. The reason for the increased risk is unclear, but immune system factors and exposure to multiple medications may play a role.

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is most often a reaction to a medication or infection. Some researchers suspect that a combination of medication and infection may trigger the condition in some people. In many cases, no particular trigger of any kind is identified.

Medications most commonly associated with SJS/TEN include:

• Antibiotics, particularly penicillins and sulfa drugs.
• Pain medicines, particularly a class of non-steroidal anti-inflammatory drugs (NSAIDs) called oxicams.
• Cough and cold medications.
• Medications used to treat seizures, such as carbamazepine, lamotrigine, and phenytoin.
• Allopurinol, which is used to treat kidney stones and a form of arthritis called gout.
• Nevirapine, which is used to treat HIV infection.

Infections that may be associated with SJS/TED include:

• Viral infections such as herpes (simplex or zoster), pneumonia, HIV, hepatitis, Coxsackie, influenza, mumps, CMV, and Epstein-Barr. Many people with the condition report a recent upper respiratory tract infection.
• Bacterial infections such as strep, diphtheria, Brucellosis, Mycobacteria, and Mycoplasma pneumoniae.

Some people may have an increased risk of developing SJS/TED. Most people with one or more risk factorsnever develop the condition, even if they are exposed to medications or infections that may trigger it. Factors that may increased a person's risk of developing SJS/TED include:

• Having HIV. The incidence of the condition among people with HIV is about 100 times greater than among people in the general population.
• Having cancer.
• Having a weakened immune system.
• Having a personal or family history of SJS/TED.
• Having certain variations of a gene called HLA-B, which is part of a family of genes called the human leukocyte antigen (HLA) complex.

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) often begins with a fever and flu-like symptoms, such as cough, sore throat, body aches, tiredness, and a general ill feeling. Within about 1 to 3 days, a reddish or purplish rash forms and the skin begins to blister and peel (detach), leading to "raw" areas of skin that are painful. These skin symptoms usually begin on the face and chest, and then spread to other parts of the body. The percentage of body surface area affected can vary significantly from person to person. When skin detachment occurs on less than 10% of the body surface, the condition is classified as Stevens-Johnson syndrome (SJS). When skin detachment occurs on over 30% of the body surface, the condition is classified as toxic epidermal necrolysis (TEN). People with 10% to 30% of the body surface affected are said to have "SJS/TEN overlap."

The mucous membranes (thin, moist tissues that line body cavities) of the mouth, throat, genitals, eyes, and/or digestive tract usually also are involved, and may become affected before or after the skin. Early symptoms of mucous membrane involvement may include light sensitivity, itching or burning of the eyes, and pain when swallowing. As the condition progresses, eye symptoms may include pain, severe conjunctivitis, discharge, iritis, and corneal blisters. Eye involvement can lead to long-term eye complications, including vision loss. Symptoms of mouth and throat involvement may include painful blisters, and trouble swallowing and breathing. Symptoms of genital involvement may include inflammation of the urethra, vaginitis, painful blisters, and difficulty urinating.Gastrointestinal symptoms may include diarrhea, black or tarry stools, and other complications.

Symptoms may persist or worsen for up to two weeks before the skin and mucous membranes begin to start healing themselves. Skin that remained attached may gradually peel during this time, and the nails may shed in some cases.

Stevens-­Johnson Syndrome (SJS), also called erythema multiforme major, is a disorder of the skin that also affects the eyes. SJS is characterized by painful blisters on the skin and the mucous membranes of the mouth, throat, genitals, and eyelids.

Often, SJS begins with flu-like symptoms, followed by a painful red or purplish rash of blisters that spread. SJS can cause severe conjunctivitis, iritis (an inflammation inside the eye), corneal blisters and erosions, and corneal holes. In some cases, SJS can lead to significant vision loss.

The most commonly cited cause of SJS is an allergic reaction to a drug or medication, particularly sulfa drugs. It is also associated with viral infections.

Treatment for the eye may include artificial tears or lubricating eye drops, antibiotics, or corticosteroids. About one third of those who develop SJS will have one or more episodes of the disease. SJS occurs twice as often in men as in women, and most often affects children and young adults under 30, although it can develop at any age.

• Saline rinses to clean the eyes and eyelids.
• Lubrication multiple times per day with preservative-free eye drops or ointments (including for those with no apparent eye involvement).
• Eye medicines with topical corticosteroids and broad-spectrum antibiotics.
• Amniotic membrane transplantation (AMT) to try to prevent vision loss and complications involving the mucous membranes. Some people need multiple procedures. The amniotic membrane is the innermost layer of the placenta, and can been used as a graft or dressing to aid in repairing the surface of the eyes and promote healing.