Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Recognizing Medication-Related Emergencies

Most people never think about their medication causing a life-threatening reaction. But for a small number of people, a common drug - like lamotrigine, allopurinol, or sulfamethoxazole - can trigger something far worse than a mild rash. It can be Stevens-Johnson Syndrome (SJS) or Toxic Epidermal Necrolysis (TEN), two sides of the same terrifying coin. These aren’t just bad skin reactions. They’re full-body emergencies that can kill. And they happen fast.

What Exactly Is SJS and TEN?

SJS and TEN are severe skin reactions caused by medications. They’re not allergies in the usual sense - no sneezing or hives. Instead, your skin starts to die. It begins with flu-like symptoms: fever, sore throat, burning eyes, fatigue. Within a few days, a painful red or purple rash spreads. Blisters form. Then your skin begins to peel off in sheets, like a bad burn. If it affects less than 10% of your body, it’s SJS. If more than 30% is involved, it’s TEN. Between 10% and 30%? That’s overlap syndrome - still dangerous.

Think of it like this: your skin isn’t just protecting you from the outside. It’s a living barrier that holds in fluids, keeps out germs, and regulates temperature. When SJS or TEN hits, that barrier collapses. You lose fluids. You get infections. Your eyes, mouth, and genitals start to erode. This isn’t something you wait out at home. It’s a hospital emergency - often in a burn unit or intensive care.

Which Medications Are Most Likely to Trigger It?

Not every drug causes this. But some are known red flags. The most common culprits include:

• Lamotrigine (used for epilepsy and bipolar disorder)
• Allopurinol (for gout)
• Carbamazepine and phenytoin (anti-seizure meds)
• Nevirapine (an HIV drug)
• Oxicam NSAIDs like meloxicam and piroxicam
• Sulfonamide antibiotics like sulfamethoxazole
• Phenobarbital

Here’s what makes it worse: if you’ve had SJS from one of these drugs before, you’re at extreme risk if you take it again - or even a similar one. Cross-reactivity is real. Someone who reacted to carbamazepine might also react to phenytoin or lamotrigine, even if they’ve never taken those before. That’s why survivors are told to avoid entire drug classes, not just the one that caused the problem.

And timing matters. Reactions usually start within the first 8 weeks of taking the drug - sometimes even after you’ve stopped it. For lamotrigine, restarting the drug after a break - even just a few days - can trigger SJS if you go back to the original dose. That’s why doctors stress slow dose increases and warn against skipping doses.

Who’s at Higher Risk?

It’s not random. Some people are more vulnerable:

• People with HIV or weakened immune systems
• Those taking sodium valproate with lamotrigine (a dangerous combo)
• People who’ve had a rash from epilepsy meds before
• Those allergic to trimethoprim
• People with a family history of SJS/TEN - there’s a strong genetic link, especially with certain HLA gene variants
• Children and young adults, though it can happen at any age

Genetics play a bigger role than most realize. For example, people of Asian descent with the HLA-B*15:02 gene are at much higher risk when taking carbamazepine. Some countries now test for this gene before prescribing it. In New Zealand, testing isn’t routine yet - but doctors should ask about family history and ethnicity when prescribing high-risk drugs.

What Happens When It Hits?

The first sign? A fever that doesn’t go away. Then, burning eyes. A sore throat that feels like you’ve swallowed glass. A rash that spreads fast - not itchy, but painfully tender. Blisters form on your lips, inside your mouth, around your genitals. Your skin turns red, then blisters, then peels off in large patches. You might lose a fingernail or two. Your eyelids stick together. Swallowing becomes impossible. Your body starts to shut down.

Doctors confirm it with a skin biopsy. Under the microscope, they see full-thickness epidermal necrosis - the top layer of skin is dead, with little inflammation. That’s the hallmark. Blood tests and imaging help check for organ damage, but the skin tells the story.

And here’s the brutal truth: the longer you wait, the higher the chance you won’t survive. Mortality jumps from 5% in SJS to over 30% in TEN. Death usually comes from sepsis, organ failure, or massive fluid loss. Some people die from a pulmonary embolism or heart attack triggered by the stress on their body.

How Is It Treated?

There’s no magic cure. Treatment is about damage control.

1. Stop the drug immediately. No exceptions. Even if you’re not sure, pull the plug.
2. Get to a hospital - now. Emergency room. Don’t wait. Don’t call your GP. Go to A&E.
3. Specialized care. Burn units are best. They know how to handle skin loss, fluid balance, and infection control.
4. Supportive care. IV fluids, pain control, wound care, nutritional support. Your skin needs time to heal.
5. Watch for complications. Eye damage is common. You’ll need daily eye exams. Mouth sores need special rinses. Urinary and genital areas must be monitored for scarring.

Some hospitals try immunomodulators like IVIG or corticosteroids, but the evidence is mixed. The best treatment? Early recognition and stopping the drug before it gets worse.

Long-Term Damage Is Real - And Often Overlooked

Survivors aren’t out of the woods. Many face lifelong problems:

• Blindness or severe vision loss in 30-50% of cases - from corneal scarring, dry eyes, or eyelids sticking shut
• Chronic dry mouth, gum disease, and tooth loss from mouth sores
• Scarring on skin, loss of pigment, or permanent nail damage
• Esophageal strictures - scar tissue making swallowing hard
• Vaginal stenosis in women, phimosis in men - scarring that affects sexual health
• Thinning hair or permanent hair loss

One woman in Auckland told her dermatologist she thought she was fine after 6 months. Then, at her yearly eye check-up, she found her cornea had scarred from untreated dryness. She lost 60% of her vision. She didn’t know her eyes needed daily drops for years. That’s why follow-up care with ophthalmologists, dermatologists, and dentists is non-negotiable.

Can It Be Prevented?

Yes - but only if you know the signs and act fast.

• If you’re prescribed lamotrigine, allopurinol, or any high-risk drug, read the warning leaflet. Keep it.
• Never start a new medication during the first 8 weeks of treatment unless your doctor says so.
• Never restart a drug after stopping it - especially lamotrigine - without your doctor’s guidance.
• If you get a rash, fever, or mouth sores while on these drugs, stop the medication and go to the hospital immediately.
• Tell your doctor if you or a family member has ever had SJS or a severe drug reaction.

Most rashes from these drugs are harmless. But if it spreads fast, hurts, or involves your mouth or eyes - don’t second-guess it. Go to the emergency department. Your life could depend on it.

What Should You Do If You Suspect SJS/TEN?

Here’s your quick action plan:

1. Stop the suspected medication immediately.
2. Call emergency services or go to the nearest hospital - do not wait.
3. Take the medication bottle with you.
4. Write down when symptoms started and what you’ve been taking.
5. Don’t try to treat it at home. No creams, no antihistamines. This isn’t an allergic rash.

Doctors in emergency rooms see thousands of rashes. But they don’t always recognize SJS. Be persistent. Say: "I think this might be Stevens-Johnson Syndrome." That phrase gets attention.

Final Thought: Know the Signs, Act Fast

SJS and TEN are rare. The chance of getting them is tiny - less than one in a million per week for even the riskiest drugs. But when it happens, it’s catastrophic. There’s no second chance to catch it early. If you’re on a high-risk medication and you feel off - fever, sore throat, burning eyes, a rash that spreads - don’t wait. Don’t check online. Don’t call your pharmacy. Go to the hospital. Your skin might be the first warning system your body has - and if you ignore it, you might not get another one.