DRESS Syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms)
A severe, delayed reaction to medication affecting the skin and internal organs
Quick Facts
- Type: Severe drug hypersensitivity reaction
- Common triggers: Anticonvulsants, allopurinol, antibiotics
- Onset: Usually 2-8 weeks after starting the drug
- Seek urgent care: Fever, spreading rash, facial swelling
Overview
DRESS syndrome, short for Drug Reaction with Eosinophilia and Systemic Symptoms, is a rare and potentially life-threatening reaction to a medication. Unlike a simple drug rash, DRESS affects the whole body: it combines an extensive skin eruption with fever, swollen glands, a rise in a type of white blood cell called eosinophils, and inflammation of one or more internal organs such as the liver, kidneys, or lungs.
A defining feature of DRESS is its delayed onset. Symptoms usually begin two to eight weeks after a person starts the triggering drug, which can make the connection to the medication easy to miss. Because the reaction can damage vital organs and may continue even after the drug is stopped, prompt recognition and medical treatment are essential.
Symptoms
DRESS typically develops gradually and then becomes more severe over days. Common features include:
- A widespread red or measles-like rash that may cover large areas of the body
- Fever, sometimes high
- Swelling of the face, especially around the eyes
- Enlarged, tender lymph nodes
- Fatigue and a general feeling of being unwell
- Signs of organ involvement, such as yellowing of the skin (liver), reduced urination (kidneys), cough or breathlessness (lungs)
Because internal organs can be affected without obvious symptoms, anyone with a spreading rash and fever after starting a new medicine should be evaluated promptly.
Causes
DRESS is an immune system overreaction to a medication. The immune cells become activated against the drug and trigger widespread inflammation. Reactivation of certain dormant viruses in the body, such as human herpesvirus 6, is thought to play a role in some cases and may explain why the reaction can flare even after the drug is withdrawn.
Medications most often linked to DRESS include certain anti-seizure drugs (such as carbamazepine, phenytoin, and lamotrigine), allopurinol (used for gout), the antibiotic group called sulfonamides, vancomycin, and some drugs for HIV and tuberculosis. Genetic differences in how a person's immune system recognizes drugs can increase susceptibility to particular medications.
Risk Factors
- Recently starting a known high-risk medication such as an anticonvulsant or allopurinol
- Certain inherited immune-system gene types (HLA variants) that affect drug sensitivity
- A previous severe drug reaction
- Underlying viral infections that can reactivate
DRESS can occur in anyone and cannot be reliably predicted in advance, which is why new symptoms during the early weeks of a medication should always be reported to a clinician.
Diagnosis
There is no single test for DRESS, so doctors diagnose it by combining the clinical picture with blood and organ tests:
- Blood tests: To look for a high eosinophil count, abnormal liver and kidney function, and atypical white blood cells.
- Medication history: A careful review to identify a drug started in the previous weeks.
- Skin examination and sometimes biopsy: To assess the rash and rule out other severe skin reactions.
- Organ testing: Imaging or further tests if the heart, lungs, or kidneys appear involved.
Doctors also distinguish DRESS from other serious drug reactions such as Stevens-Johnson syndrome.
Treatment
The single most important step is to stop the suspected medication immediately and never take it again. Beyond that, treatment focuses on calming the immune reaction and supporting affected organs:
- Corticosteroids: Systemic steroids are commonly used to reduce inflammation, often tapered slowly over weeks to prevent flares.
- Supportive care: Fluids, skin care, fever control, and monitoring of liver, kidney, and heart function, often in hospital.
- Specialist input: Dermatology, and sometimes other specialists, guide care for severe organ involvement.
Most people recover with prompt treatment, but recovery can take weeks, and symptoms may temporarily worsen even after the drug is stopped. Long-term follow-up is advised because some patients later develop thyroid or other autoimmune problems.
Prevention
- Tell every healthcare provider about any past severe drug reaction
- Carry a clear record or alert listing the medication that caused DRESS
- Avoid the trigger drug and closely related medicines for life
- Where available, genetic screening before high-risk medications can help some patients avoid known triggers
- Report new fever or rash early when starting a new long-term medication
When to See a Doctor
Seek urgent medical care if, in the weeks after starting a new medication, you develop a spreading rash together with fever, facial swelling, or swollen glands. Go to an emergency department right away if you have:
- A rapidly worsening rash with peeling skin or blisters
- Yellowing of the skin or eyes, or very dark urine
- Difficulty breathing, chest pain, or confusion
- Reduced urination or severe swelling
DRESS can become life-threatening, so do not wait to see whether symptoms pass on their own.
Frequently Asked Questions
How soon after starting a drug does DRESS syndrome appear?
DRESS usually begins two to eight weeks after starting the triggering medication, which is later than most allergic reactions. This delay can make it hard to connect the symptoms to the drug, so any rash with fever in the weeks after a new medicine should be checked.
Is DRESS syndrome an emergency?
Yes. DRESS can inflame internal organs such as the liver and kidneys and can be life-threatening. If you develop a spreading rash with fever and facial swelling after starting a medication, seek medical care promptly and stop the suspected drug under medical guidance.
Which medications most commonly cause DRESS?
Common triggers include certain anti-seizure drugs such as carbamazepine and phenytoin, allopurinol used for gout, sulfonamide antibiotics, vancomycin, and some HIV and tuberculosis medications. Many other drugs can occasionally cause it.
Can DRESS get worse after the drug is stopped?
Yes, symptoms can continue or even flare for days to weeks after the medication is withdrawn, partly because of associated viral reactivation. This is why hospital monitoring and a slow steroid taper are often needed.
Can DRESS syndrome come back?
The same reaction will recur, often faster and more severely, if you take the triggering drug or a closely related one again. Avoid the culprit medication for life and make sure all your healthcare providers know about it.
References
- MedlinePlus, U.S. National Library of Medicine. Drug reactions.
- National Organization for Rare Disorders (NORD). DRESS Syndrome.
- American Academy of Dermatology. Severe drug reactions.
- Genetic and Rare Diseases Information Center (GARD). Drug reaction with eosinophilia and systemic symptoms.