Stevens-Johnson Syndrome: Causes, Symptoms, and Treatment — Full Guide
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
TL;DR
Stevens-Johnson syndrome (SJS) is a rare, life-threatening skin and mucous membrane disorder, most often triggered by medication or infection. It starts with flu-like symptoms, then a painful spreading rash and blistering that can shed the skin's top layer. It is a medical emergency requiring hospitalization. Early recognition, immediate drug withdrawal, and specialized supportive care are what save lives and determine how fully a person recovers.
Quick Answer
Stevens-Johnson syndrome is a rare, serious disorder of the skin and mucous membranes, usually triggered by a medication reaction or infection. It begins with fever, sore throat, fatigue, and burning eyes one to three days before a painful rash appears, spreads, and blisters. The top layer of affected skin then dies and sheds. SJS is a medical emergency that requires hospitalization — often in an intensive care or burn unit. Treatment focuses on stopping the suspected drug, fluid and wound care, pain control, and preventing complications such as sepsis and eye damage. Recovery takes weeks to months, and the triggering drug must be permanently avoided [1].
Editorial note: This guide is based on source-only reporting from major medical institutions, including Mayo Clinic (updated April 2025), NIH StatPearls, and MedlinePlus Genetics. It is intended for education only and is not a substitute for professional medical advice. If you suspect SJS, call emergency services immediately.
What is Stevens-Johnson syndrome?
Stevens-Johnson syndrome (SJS) is a rare but serious disorder of the skin and mucous membranes. It is usually a reaction to a medication that begins with flu-like symptoms, followed by a painful rash that spreads and blisters. The top layer of affected skin dies, sheds, and begins to heal over several days [1].
It is a medical emergency that almost always requires hospitalization. A more severe form of the same condition is called toxic epidermal necrolysis (TEN), which involves more than 30 percent of the skin surface and extensive damage to the mucous membranes. Full recovery can take weeks to months [1].
SJS and TEN are now understood as opposite ends of one disease spectrum. SJS affects less than 10 percent of body surface area, the SJS/TEN overlap affects 10 to 30 percent, and TEN affects more than 30 percent [2].
How common is Stevens-Johnson syndrome?
SJS is rare. Across most populations, it affects approximately 1 to 5 cases per 1 million people each year, with a higher incidence in adults than in children [2]. The National Library of Medicine's MedlinePlus Genetics puts the SJS/TEN combined frequency at 1 to 2 per million people annually, with SJS being the more common of the two [3].
In a long-term United Kingdom population study covering 1995 to 2013, researchers calculated 5.76 validated SJS/TEN cases per million person-years [2]. For context on severity: roughly 10 percent of people with SJS die from the disease, while TEN is fatal in up to 50 percent of cases [3].
Statistic | Figure |
Annual incidence (most populations) | 1–5 cases per 1 million people (NIH StatPearls, 2026) [2] |
Annual incidence (UK, 1995–2013 study) | 5.76 per 1 million person-years (NIH StatPearls, 2026) [2] |
Mortality rate for SJS | ~10% (MedlinePlus Genetics, 2020) [3] |
Mortality rate for TEN | Up to 50% (MedlinePlus Genetics, 2020) [3] |
Share of cases caused by a single drug | 86% (95% CI, 80–92%) (JAMA Dermatology, 2023) [4] |
Cases where medication is the trigger | More than 80% (NIH StatPearls, 2026) [2] |
More than 80 percent of cases result from medication exposure, and a 2023 meta-analysis published in JAMA Dermatology found that a single drug was associated with 86 percent of all SJS/TEN cases [2] [4].
What are the early warning signs of Stevens-Johnson syndrome?
Timing matters enormously with SJS. One to three days before a rash develops, the body often gives early warning signs that are easy to mistake for an ordinary viral illness [1].
Early signs include:
Fever
Sore mouth and throat
Fatigue
Burning eyes
Because these symptoms look like the flu, SJS is frequently missed at this stage. The critical differentiator is what follows: drug-induced reactions can appear during the use of a medication or up to two weeks after stopping it, and they are followed by widespread skin pain and a spreading rash rather than resolving on their own [1].
What does the Stevens-Johnson syndrome rash look like?
As the condition develops beyond the early flu-like phase, signs and symptoms include [1]:
Unexplained widespread skin pain
A red or purple rash that spreads
Blisters on the skin and the mucous membranes of the mouth, nose, eyes, and genitals
Shedding of skin within days after blisters form
The rash typically starts on the face and chest before spreading. In most affected individuals, the mucous membranes are also damaged, including the lining of the mouth and airways, which can cause trouble swallowing and breathing. MedlinePlus describes the raw, peeled areas as erosions that "resemble a severe hot-water burn" [3].
When is Stevens-Johnson syndrome an emergency?
SJS requires immediate medical attention. Call emergency services or go to an emergency room right away if you or someone you are with shows signs of this condition — especially if a new medication was started in the previous three weeks [1].
If there is time before going, pack a bag with all medications taken in the last three weeks, including prescription and over-the-counter drugs. That bag can help doctors quickly identify the trigger [5]. A family member or friend should come along to share relevant health information [5].
Questions your health care provider will likely ask include [5]:
Have you had a flu-like illness recently?
What other medical conditions do you have?
What medications have you taken in the last three weeks?
What causes Stevens-Johnson syndrome?
SJS is rare and unpredictable, and a provider may not always be able to identify the exact cause. But it is usually triggered by medication, an infection, or both. A reaction can occur while using a medication or up to two weeks after discontinuing it [1].
Immunologically, SJS is classified as a type IV (delayed) hypersensitivity reaction. Activated T cells release a substance called granulysin that destroys cells in the skin and mucous membranes, causing the characteristic blistering and peeling [3].
Medications most often linked to SJS
Drugs that can cause Stevens-Johnson syndrome include [1] [2]:
Anti-gout medication, such as allopurinol
Seizure and mental illness medications (anticonvulsants and antipsychotics), including lamotrigine, carbamazepine, and phenytoin
Antibacterial sulfonamides (sulfamethoxazole combinations, sulfasalazine)
Nevirapine, an HIV medication
Pain relievers such as acetaminophen, ibuprofen, and naproxen
Nonsteroidal anti-inflammatory drugs (NSAIDs), including the oxicam class
Infections that can cause SJS include pneumonia — particularly Mycoplasma pneumoniae — and HIV [1] [2].
Trigger category | Examples | Notes |
Anti-gout drugs | Allopurinol | Strong association across multiple studies |
Anticonvulsants | Carbamazepine, lamotrigine, phenytoin, valproic acid, phenobarbital | Highest-risk antiepileptic class; genetic screening available for some |
Antipsychotics | Various | Listed by Mayo Clinic as a risk class |
Sulfonamide antibiotics | Sulfamethoxazole combinations, sulfasalazine | Most strongly linked antibiotic class |
HIV medications | Nevirapine | Carries specific warnings |
NSAIDs / pain relievers | Acetaminophen, ibuprofen, naproxen, oxicams | Rare but documented; FDA has issued safety communications |
Infections | Mycoplasma pneumoniae, HIV, hepatitis A | Leading cause in children |
Most cases develop 4 to 28 days after initial exposure to the drug, and drugs with longer half-lives carry higher risk because they persist in the body longer [2].
Who is at higher risk of Stevens-Johnson syndrome?
Several factors measurably increase risk [1] [2] [3]:
An HIV infection. Among people with HIV, the incidence of SJS is about 100 times greater than in the general population.
A weakened immune system, from an organ transplant, HIV/AIDS, or autoimmune diseases such as lupus.
Cancer, particularly blood cancer.
A history of SJS. Re-exposure to the triggering drug risks a recurrence, which is usually more severe than the first episode and can be fatal.
A family history of SJS. If an immediate blood relative has had the condition, risk is elevated.
Genetic factors. Certain variations in the HLA-B gene put people at increased risk, especially when taking seizure, gout, or mental illness drugs. The HLA-B*1502 variant in Han Chinese and Southeast Asian populations is strongly associated with carbamazepine-induced SJS/TEN, and Asian and Black patients have shown a two- to three-fold increased risk compared with White patients [2] [3].
Adults are affected more often than children. In adults, cases are mainly drug-induced; in children, infections are the leading cause [2].
How is Stevens-Johnson syndrome diagnosed?
Doctors typically diagnose SJS through a combination of history, examination, and testing [5]:
Medical history and physical exam. Providers can often identify SJS from a review of current and recently stopped medications combined with a physical exam.
Skin biopsy. A sample of skin is removed for laboratory testing to confirm the diagnosis and rule out other causes.
Culture. Skin, tissue, or fluid samples are tested to rule out infection.
Imaging. A chest X-ray may be used to check for pneumonia.
Blood tests. These confirm infection or other possible causes.
How is Stevens-Johnson syndrome treated?
Treating SJS requires hospitalization, possibly in an intensive care unit or a burn unit [5].
Step one: stop all nonessential medications
The first and most important step is to stop taking any medications that may be causing the reaction. If you take more than one drug, it may be hard to tell which one is responsible, so a provider may stop all nonessential medications at once [5].
Supportive care
Supportive care in the hospital includes [5]:
Fluid replacement and nutrition. Skin loss causes significant fluid loss, so replacing fluids is a core part of treatment. Fluids and nutrients may be delivered through a nasogastric tube.
Wound care. Cool, wet compresses can soothe blisters. The care team may gently remove dead skin and apply petroleum jelly or medicated dressings.
Eye care. An eye specialist (ophthalmologist) is often involved.
Medications
Pain medication to reduce discomfort
Topical steroids to reduce inflammation of the eyes and mucous membranes
Antibiotics when infection needs to be controlled
Systemic options, including corticosteroids and intravenous immune globulin; studies show the drugs cyclosporine and etanercept are helpful in treating this disease [5]
If the underlying cause is eliminated and the skin reaction stops, new skin may begin to grow within several days. In severe cases, full recovery may take several months [5].
What are the complications of Stevens-Johnson syndrome?
SJS complications can be severe and some are permanent [1]:
Dehydration. Shed skin loses fluids, and sores in the mouth and throat can make drinking difficult.
Blood infection (sepsis). Bacteria entering the bloodstream cause a rapidly progressing, life-threatening condition that can cause shock and organ failure.
Eye problems. The rash can cause eye inflammation, dry eye, and light sensitivity. Severe cases can lead to visual impairment and, rarely, blindness.
Lung involvement. The condition may cause acute respiratory failure, an emergency in which the lungs cannot get enough oxygen into the blood.
Permanent skin damage. Regrown skin may have bumps, unusual coloring (dyspigmentation), and scars. Lasting effects can include hair loss and impaired fingernail and toenail growth [1] [3].
Survivors may also experience chronic dryness or inflammation of the eyes, impaired taste, difficulty urinating, and genital abnormalities [3].
Can Stevens-Johnson syndrome be prevented?
Complete prevention is not possible because the condition is rare and unpredictable, but two evidence-based strategies reduce risk [1]:
Consider genetic testing before starting certain drugs. The FDA recommends screening people of Asian and South Asian ancestry for the HLA-B*1502 gene variant before starting carbamazepine. This is one of the clearest examples of pharmacogenomic prevention in dermatology.
If you have had SJS, avoid the trigger drug permanently. If a provider determined your SJS was caused by a medication, avoid that drug and others like it. This is key to preventing a recurrence, which is usually more severe than the first episode and can be fatal. Immediate blood relatives may also want to avoid the drug, because the condition sometimes runs in families [1].
If you have had SJS, carry that information with you at all times: know the name of the medication that caused it, inform every health care provider of your history, and wear a medical information bracelet or necklace inscribed with your condition and its cause [5].
What to ask your doctor about Stevens-Johnson syndrome
It can help to keep a list of questions, such as [5]:
What caused my condition?
How do I keep from having this reaction again?
What restrictions do I need to follow?
I have other medical conditions — how do I manage them together?
How long will it take my skin to heal?
Am I likely to have any permanent damage?
Conclusion
Stevens-Johnson syndrome is rare, but its consequences are severe enough that every hour counts. It almost always begins as something that looks like the flu — fever, sore throat, fatigue, burning eyes — shortly after starting a new medication. Within days, that flu-like picture turns into widespread skin pain, a spreading red or purple rash, and blisters on the skin and mucous membranes.
The three actions that determine outcomes are well established: get emergency care immediately, stop the suspected drug, and receive specialized hospital support focused on fluids, wounds, eyes, and infection prevention. Knowing your medication history, asking about genetic screening before starting high-risk drugs, and permanently avoiding any proven trigger are the most powerful prevention tools available.
If you or someone you know develops an unexplained spreading rash with fever after starting a new medication, call emergency services now. Early treatment saves skin, eyesight, and lives.
For education only; consult a qualified health professional for diagnosis and treatment.
Frequently Asked Questions
What is Stevens-Johnson syndrome?
Stevens-Johnson syndrome is a rare, serious disorder of the skin and mucous membranes, usually caused by a reaction to medication or an infection. It starts with flu-like symptoms, followed by a painful, spreading rash that blisters and sheds the top layer of skin. It is a medical emergency requiring hospitalization [1].
Is Stevens-Johnson syndrome contagious?
No. SJS is not contagious. It is an immune-mediated reaction, most often a type IV hypersensitivity response to a medication, in which immune cells release granulysin that damages skin and mucous membrane cells [2] [3].
What does Stevens-Johnson syndrome look like at the start?
One to three days before a rash appears, early signs include fever, sore mouth and throat, fatigue, and burning eyes — symptoms that closely resemble the flu. The rash that follows is red or purple, spreads, blisters on the skin and mucous membranes, and sheds within days [1].
How long does Stevens-Johnson syndrome last?
Recovery takes weeks to months. If the cause is removed and the reaction stops, new skin may begin to grow within several days, but severe cases can take several months for full recovery [1] [5].
Can Stevens-Johnson syndrome be cured?
There is no single cure. Treatment focuses on removing the cause (stopping the suspected drug), supportive hospital care, controlling pain, and preventing complications. When the cause is eliminated, the skin heals and regrows over weeks to months [1] [5].
Can Stevens-Johnson syndrome come back?
Yes. Re-exposure to the drug that triggered SJS can cause a recurrence, and recurrences are usually more severe than the first episode and can be fatal. The triggering drug and similar medications must be permanently avoided, and some cases run in families [1].
How do you know if a rash is Stevens-Johnson syndrome?
A rash is concerning for SJS when it follows a new medication by one to four weeks, is preceded by fever, sore throat, and burning eyes, causes unexplained widespread skin pain, spreads rapidly, and involves blistering of the skin plus the mucous membranes of the mouth, eyes, nose, or genitals. When in doubt, seek emergency care immediately [1] [5].
What is the mortality rate of Stevens-Johnson syndrome?
About 10 percent of people with SJS die from the disease, while the more severe form, toxic epidermal necrolysis, is fatal in up to 50 percent of cases. Mortality rises with the percentage of body surface area involved [3].
References
NIH StatPearls — Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis
MedlinePlus Genetics — Stevens-Johnson syndrome/toxic epidermal necrolysis
JAMA Dermatology (2023) — Worldwide Prevalence of Antibiotic-Associated SJS/TEN
Mayo Clinic — Stevens-Johnson syndrome: Diagnosis & treatment
FDA — Drug safety communication on acetaminophen and serious skin reactions
Comments