What Is DRESS Syndrome, and What Causes It?

Hives, rashes, and trouble breathing are all potential signs of an allergic reaction. One potential trigger for allergic reactions is starting a new medication. In very rare cases, medication allergies can be dangerous or life-threatening.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is one example of a serious medication allergy. It’s a type of severe allergic reaction to a medication that occurs 2 to 8 weeks after starting a medication. DRESS syndrome is characterized by fever, rash, abnormal blood tests, and swollen lymph nodes (small glands that filter foreign substances and contain cells that help the body fight infection). The condition also affects at least one internal organ — most often the liver.

DRESS syndrome is rare — it affects 1 in 1,000 to 1 in 10,000 people exposed to a medication. But it’s a life-threatening condition.

Below, we’ll discuss potential symptoms of DRESS, medications that are closely linked with the condition, and people who may have a greater chance of developing this severe allergic reaction.

What are the symptoms of DRESS syndrome?

There isn’t one test that can confirm if a person has DRESS syndrome. Rather, healthcare professionals use criteria to help them diagnose the condition.

These criteria state that at least three of the following should be present to consider a DRESS syndrome diagnosis:

• A person is in the hospital

• A fever greater than 100.4℉ (38℃)

• A sudden rash develops — usually redness involving the entire body, followed by peeling

• Enlarged lymph nodes in at least two areas of the body

• Problems with at least one internal organ, such as the liver, thyroid, kidney, lung, or heart

• Abnormal blood levels of lymphocytes (a white blood cell), eosinophils (another white blood cell), or platelets (a blood component necessary for forming blood clots)

• Suspicion that these symptoms may be related to a medication

Most of these criteria would be discovered by a healthcare professional. But there are two you can watch for at home. If you ever develop a sudden, severe rash along with a fever, seek medical attention right away.

What causes DRESS syndrome?

The precise cause of DRESS syndrome isn’t well understood. But it’s thought that some cases may be caused by difficulties in the way the liver breaks down certain medications. Reactivation of a virus — when a virus that is inactive in your body becomes active again — may also play a role by triggering the immune system to overreact.

One example of a virus linked to DRESS syndrome is Epstein-Barr virus, a virus that causes mononucleosis (“mono”). Many people may have had this infection during childhood or early adulthood. It often remains inactive for a lifetime, causing no problems. It’s unclear why this or other viruses become active again for some people.

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Which medications can cause DRESS syndrome?

There’s a delay between the moment a person starts a medication and when DRESS syndrome symptoms begin. This is quite different from many common medication reactions, which often occur within hours or days of taking a medication. With DRESS syndrome, the reaction can occur 2 to 8 weeks after starting a medication and continue even after stopping it.

The medications most frequently associated with DRESS syndrome are:

• Anti-seizure medications, especially lamotrigine (Lamictal), carbamazepine (Tegretol), and phenobarbital

• Allopurinol (Zyloprim), a gout medication

• Antibiotics, especially minocycline (Minocin), vancomycin (Vancocin), and those that are sulfa based

• Sulfasalazine (Azulfidine), a medication used to treat autoimmune diseases such as rheumatoid arthritis and ulcerative colitis

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) and celecoxib (Celebrex, Elyxyb)

• Certain antiviral medications, most commonly nevirapine (Viramune)

• Certain cancer medications, such as vemurafenib (Zelboraf)

This isn’t an all-inclusive list of medications that can cause DRESS syndrome. Ask your prescriber or pharmacist if any of your medications are known to cause this condition.

Is DRESS syndrome a medical emergency?

Yes. People with this condition typically require a hospital stay to manage and treat the condition. An intensive care unit (ICU) setting may also be necessary because DRESS syndrome can seriously affect internal organs.

Because DRESS syndrome can be life-threatening, early diagnosis and treatment are essential. A delay in treatment could have grave consequences.

How do you treat DRESS syndrome?

There are many ways DRESS syndrome can be treated. It depends on your symptoms and medical history. Below is information on some of the DRESS treatments healthcare professionals may use.

Stop the medication that likely triggered DRESS syndrome

First, it’s crucial to stop the triggering medication. This can pose a challenge if the person takes multiple medications. Be sure to give your healthcare team a list of all your medications, including over-the-counter and herbal products.

Supportive care

Because internal organs — such as the liver, kidney, heart, and lung — are often affected, almost all people affected will need supportive care in an ICU or a burn unit setting. Supportive care can include dialysis for kidney problems and medications to help relieve heart, lung, and liver symptoms.

Steroids

Oral or IV corticosteroids (steroids) — such as prednisone or methylprednisolone — help calm down the immune system’s reaction and prevent further organ damage. Typically, oral steroid doses are slowly decreased (tapered) over weeks or months after the initial treatment is complete. Steroid creams can help manage rash symptoms, such as itching.

Antiviral medications

Antiviral medications may be useful in some cases — such as when DRESS syndrome is thought to be linked to virus reactivation. Ganciclovir is one example of an antiviral medication that’s been used to treat DRESS syndrome linked to viral reactivation.

Keep in mind that antivirals aren’t appropriate for everyone who develops DRESS syndrome. There are reports of people who developed the condition after taking antiviral medications.

What is the outlook for someone with DRESS syndrome?

DRESS syndrome can be life-threatening. But with prompt diagnosis and removal of the triggering medication, most people will recover completely.

Even so, long-term problems due to DRESS syndrome are still possible. Examples of long-term DRESS syndrome complications include:

• Alopecia areata (a condition that causes hair loss)

• Type 1 diabetes

• Hemolytic anemia (when red blood cells are abnormally destroyed)

• Myocarditis (inflammation of the heart muscle)

• Mental health conditions, including anxiety or depression

• Inflammation of the thyroid gland

• Lupus

Which factors raise your risk of getting DRESS syndrome?

Experts aren’t fully clear on all the possible risk factors for developing DRESS syndrome. Some potential risk factors include:

• Genetics: Some genes play a role in how your body breaks down certain medications. If the body isn’t breaking down medications as expected, there’s concern that DRESS syndrome could occur. Certain genetic traits may contribute to a person’s risk of developing the condition.

• Raising medication doses too fast: Rapidly raising the dose when first starting certain medications may also be linked to DRESS syndrome. For example, the anti-seizure medication lamotrigine has a boxed warning (the FDA’s strictest medication warning) stating that this condition has been reported in people who started with higher doses than what’s recommended.

• Virus reactivation: There may be connection with certain viral infections and more severe DRESS syndrome symptoms. People with DRESS syndrome who test positive for reactivation of certain viruses tend to have longer hospital stays and worse outcomes.

What can you do to lower your chances of getting DRESS syndrome?

If anyone in your family has experienced DRESS syndrome, tell your healthcare team. Some genetic markers may raise your chance of developing a reaction to certain medications. Your prescriber may be able to screen you for these genetic markers and advise you if you should be cautious with certain medications.

If you’re prescribed a medication in which the dose is raised slowly in the beginning, this is most likely done to lower your risk of complications, quite possibly for DRESS syndrome. Be sure to follow your healthcare team’s instructions carefully, and always double check with them if you’re unsure of your dose.

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Written by:

Valerie Hanft, MD

Valerie Hanft, MD, has practiced general medical and pediatric dermatology for 20 years. She has served on the FDA Task Force, participated in many clinical trials, and authored multiple peer-reviewed publications.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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