Stevens-Johnson syndrome (SJS) is a rare and extremely serious condition that causes your skin to come loose and detach.

It was once known as Lyell’s syndrome, and it’s sometimes mistakenly called “Steven Johnson syndrome.” SJS is related to toxic epidermal necrolysis (TEN), and they are similar diagnoses, but TEN is a more severe condition.

In more than 80 percent of cases, SJS is caused by an unpredictable adverse reaction to medication. It’s less frequently caused by infections.

Researchers report that there are four to five cases of SJS for every 1 million adults annually.

While SJS is rare, it’s also life threatening and should be treated immediately.

MEDICAL EMERGENCY

If you suspect you have SJS, call emergency services or visit an emergency care facility right away. SJS often progresses along the following course:

  • You’ve taken new medication within the last 8 weeks.
  • You have flu symptoms.
  • You have a rash on your face or chest that spreads to mucous membranes, which run from your nose to your lungs.
  • You experience blistering.

The hallmark symptom of SJS is a blistering rash that involves your mucous membranes.

In many cases, you’ll experience other symptoms 1 to 3 days before the rash begins. Often, the first symptom is fever. Other early symptoms may include:

When the rash begins, your skin may have pink spots that are darker in the middle. These areas could be flat or slightly raised. The spots can become a darker red or purple color as symptoms progress.

The rash usually starts on the face and chest before spreading to the mucous membranes, most often your lips and the inside of your mouth, but it could also appear on your:

  • eyes and eyelids
  • genitals
  • esophagus
  • upper respiratory tract
  • anus

In some places, the rash will blister and the epidermis — the outermost layer of your skin — dies and peels.

Rashes caused by SJS can occur anywhere, but they will usually begin on your face or chest and later spread across your body. Mucous membranes are also affected, with about half of people with SJS developing rashes on three separate mucosal sites.

Below are pictures of typical rashes caused by SJS.

SJS is most commonly caused by an immune response to certain medications. It’s also possible for some infections to cause SJS.

Some experts have suggested that a combination of medications and infections could together cause SJS, while in some cases, the trigger is never identified.

Medications

While more than 100 medications have been associated with SJS, they generally fall into a handful of categories. SJS develops within a few days to 8 weeks after first taking the new medication.

Medications associated with SJS include:

Infections

There are two main categories of infections that are associated with SJS: viral and bacterial. Viral infections associated with SJS include:

Bacterial infections associated with SJS include:

Vaccines

There have been reports of SJS linked to vaccinations, although it is extremely rare, totaling around a dozen known cases and associated with nearly as many different vaccines. There is no clear pattern or specific vaccine to be aware of.

SJS can affect anyone, but it’s more common in women and older people. It’s also been reported that SJS is more common in children.

Certain medical conditions are risk factors for SJS, including:

Your genes are also a risk factor for SJS. If a close family member has had SJS or TEN, your risk of SJS is increased.

Variations of the gene HLA-B are associated with an increased risk of SJS and can sometimes be found in people of various ethnic identities, including:

  • Han Chinese
  • Thai
  • Malaysian
  • South Indian
  • Taiwanese
  • Japanese
  • Korean
  • European

Without genetic testing, you probably will not know if your genes are affected. Doctors might order a genetic test to assess your risk level before treating you with certain medications.

If you’ve had SJS or TEN before, you have a higher risk of another occurrence and should avoid known triggers.

SJS and TEN are on the same spectrum of disease, but they are different diagnoses. The determining factor is the amount of skin that’s affected:

  • 10 percent or less is considered SJS.
  • 10 to 30 percent is considered an overlap, abbreviated SJS/TEN.
  • 30 percent or more is considered TEN.

While SJS is the least severe of these diagnoses, it’s still life threatening and should be treated immediately.

Because SJS affects your skin and mucous membranes, those areas are at risk for complications, which can include:

You can also experience severe complications from SJS inside of your body, including:

If you receive a diagnosis of SJS, you’ll immediately be admitted to a hospital, potentially the intensive care unit (ICU), a specialized burn unit, or dermatology unit.

If you’re taking medications that could cause SJS, you’ll stop taking them. Treatment will focus on symptom management and preventing complications, like secondary infections.

Skin care will be a primary focus of treatment, including cleaning, dressing, and removing dead tissue.

Other treatments include:

SJS must be treated immediately.

Although early symptoms usually resemble that of a flu, you should seek medical help right away if you also meet any of the following criteria:

  • started taking new medication in the last 8 weeks
  • have a rash that you believe may be SJS
  • have a family history of SJS or TEN
  • have a previous diagnosis of SJS or TEN

There is no specific test or criteria to diagnose SJS.

A doctor, often a specialist like a dermatologist, will diagnose your condition based on your medical history and the symptoms you’re experiencing.

Doctors may take a skin sample, called a biopsy, or perform other diagnostic tests to help confirm SJS and rule out other conditions.

The only method of preventing SJS is to minimize your risk where possible.

If you’ve previously had SJS or TEN, avoid previous triggers and medications associated with SJS. This is also relevant if you have not had SJS or TEN but a family member has.

Before starting medication that could trigger SJS, your doctor might review your genes for variations that may increase your risk of SJS.

Recovery from SJS will look different for everyone, depending on the severity of symptoms and complications. SJS is sometimes fatal — reportedly 2 to 5 percent of cases — but these numbers have been improving as treatments get better.

Skin will start to regrow in 2 to 3 weeks but could take several months to fully return. Other symptoms or complications will have a range of recovery times and can have permanent effects.

SJS can take a mental toll in addition to the physical symptoms. If you’ve had SJS, speak with a healthcare professional if you’re feeling depressed or anxious.

SJS is a rare condition, but when it happens, it’s a medical emergency.

Symptoms might resemble a flu at first, but a rash will usually appear within a few days. The rash will spread to the mucous membranes and will peel and blister.

Certain medications can cause SJS. Less frequently, it can be the result of an infection. Your genes can increase your risk of SJS.

If you receive a diagnosis of SJS, you can expect to be admitted to a hospital right away. The sooner you begin treatment, the better.

After you’ve had SJS, your doctor will advise you on how to avoid getting it again.