Stevens-Johnson syndrome is almost always caused by a medication. A drug triggers a rare, severe immune system reaction in which the body attacks itself. Its own defenses turn against the skin and mucous membranes from within, causing SJS, or worse, TEN.
When that reaction involves more than 30% of the body’s surface area, the diagnosis escalates from SJS to toxic epidermal necrolysis (TEN); TEN is exclusively caused by drugs.
Certain drug categories appear in SJS cases far more consistently than others. At Dunn Sheehan, we have tracked those categories through decades of litigation. Understanding which ones—and whether yours is among them—is where this starts.
The Drug Categories Most Closely Linked to SJS
Three categories of drugs appear most consistently across SJS case literature, FDA safety data, and litigation.
- Antibiotics
- Antiepileptic Drugs
- Oncology Drugs
Each of these categories has a documented history in SJS cases. Not as a rare coincidence, but as a recurring pattern across case reports, regulatory communications, and courtroom evidence.
Identifying What Caused Your SJS
“Which drug caused this” is what the treating team needs to answer, and it’s also what a legal claim rests on. If someone was taking more than one medication when symptoms appeared, the timing of when each drug was started relative to when symptoms emerged matters.
SJS symptoms typically appear within days to a few weeks of starting the triggering drug. A medication introduced 2 days before the onset window carries different legal significance than one started 6 months earlier.
Next, we look at the manufacturer’s label. The question of what that label said and whether it reflected what the manufacturer’s own safety data showed is where the medical cause connects to legal liability. The drug is what causes Stevens-Johnson syndrome, but the manufacturer’s failure to communicate that risk is what creates our claim.
What Every Major Manufacturer Already Knows About Dunn Sheehan
We have litigated the causation question—which drug triggered the reaction and whether the manufacturer warned about the SJS risk adequately. We’ve done this against nearly every major pharmaceutical company in the country.
These are not theoretical arguments. They are claims our firm has built, tested, and won across hundreds of cases involving antibiotics, antiepileptic medications, oncology drugs, and others. Over $100M in results reflects that record.
That pattern has a name. It’s called a winning case.
Frequently Asked Questions About What Causes Stevens-Johnson Syndrome
Can antibiotics cause Stevens-Johnson syndrome?
Yes. Antibiotics are among the most frequently documented SJS triggers. Sulfa-based antibiotics carry the highest risk within this class, though case reports and FDA safety data connect SJS with multiple other antibiotic types as well. Any rash or flu-like symptoms that develop during an antibiotic course should be evaluated by a medical provider immediately.
Can sulfa antibiotics cause SJS?
Sulfonamide antibiotics—often called sulfa drugs—are among the most consistently documented SJS triggers in case literature and regulatory safety data worldwide.
Trimethoprim-sulfamethoxazole (Bactrim®) carries one of the highest documented SJS associations within this antibiotic group. Any new rash, fever, or systemic symptoms during a sulfa antibiotic course warrant immediate medical evaluation.
Can anti-epileptic drugs be what causes Stevens-Johnson syndrome?
They can. Several antiepileptic medications have well-established SJS associations, particularly in the first weeks of treatment. Carbamazepine (Tegretol®), phenytoin (Dilantin®), and phenobarbital are among those most frequently cited in case reports and FDA communications.
Can oncology drugs cause SJS?
Yes. PD-1 inhibitor checkpoint drugs (a class of cancer immunotherapy) have been linked to both SJS and TEN. These medications work by broadly activating the immune system to target cancer cells. That same mechanism can trigger severe skin and mucous membrane reactions in some patients. This drug class recognizes SJS and TEN as adverse events.
Can allopurinol cause Stevens-Johnson syndrome?
Allopurinol, prescribed to lower uric acid and manage gout or certain kidney stones, is among the most frequently cited SJS and TEN triggers in international case series.
Can ibuprofen cause Stevens-Johnson syndrome?
Ibuprofen, which is a non-steroidal anti-inflammatory drug (NSAID) that is sold under brand names including Advil® and Motrin® has been documented in SJS case reports, including in pediatric patients. While the reaction is rare, it can occur with over-the-counter medications. Any rash, fever, mouth sores, or eye pain that develops after taking ibuprofen warrants prompt medical evaluation.
What to Have Ready Before You Call
You don’t need to have everything figured out. You don’t need a complete file, a clear timeline, or even certainty about which medication caused your symptoms. Most families who call Dunn Sheehan are still in the middle of it and that’s exactly when we’re ready to help.
If you have any of the following, go ahead and share them with our team:
- A list of medications you were taking when symptoms first appeared
- The approximate date symptoms began
- Hospital records, discharge summaries, or admission notes
- Prescription labels or pharmacy printouts
- Photos of the rash or skin progression, if available
If you don’t have any of these things, that’s okay. We know how to get what we need.
Furthermore, there is no upfront cost. At Dunn Sheehan, we work on contingency, meaning you pay nothing unless we recover for you.
