Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
A rare, severe delayed drug reaction affecting the skin and organs
Quick Facts
- Type: Severe drug hypersensitivity reaction
- Onset: Typically 2 to 8 weeks after starting a drug
- Hallmarks: Rash, fever, high eosinophils, organ involvement
- Action needed: Stop the drug and seek urgent care
Overview
Drug reaction with eosinophilia and systemic symptoms, known as DRESS, is a rare but serious reaction to a medication. Unlike a simple drug rash, DRESS involves the whole body: a widespread rash, fever, swollen lymph nodes, a high count of eosinophils (a type of white blood cell), and inflammation of internal organs such as the liver, kidneys, lungs, or heart.
A key feature of DRESS is its delayed onset, usually appearing two to eight weeks after starting the responsible drug, which can make the link to the medication harder to recognize. DRESS is potentially life-threatening, particularly because of organ involvement, so it is treated as a medical emergency. The first and most important step is stopping the medication that caused it. With prompt recognition and treatment, many people recover, though it requires close medical care.
Symptoms
DRESS usually begins with fever and a rash, followed by signs of organ involvement. Symptoms can include:
- Fever, sometimes high
- A widespread red rash that may cover much of the body and can involve facial swelling
- Swollen lymph nodes
- Facial puffiness, especially around the eyes
- Feeling generally very unwell
- Signs of organ inflammation, such as yellowing of the skin (liver), reduced urine (kidneys), or cough and breathlessness (lungs)
DRESS is a medical emergency. Seek urgent care for a spreading rash with fever, facial swelling, or feeling severely unwell after starting a new medication, especially within the past several weeks. Stop the suspected drug and get evaluated right away.
Causes
DRESS is caused by a severe, delayed immune reaction to a medication. Certain drugs are more frequently associated with it, including:
- Some anti-seizure medications
- Certain antibiotics, including some sulfa drugs and others
- The gout medication allopurinol
- Some other drugs, including certain antiretroviral and anti-inflammatory medicines
The immune system reacts to the drug in a way that activates eosinophils and causes widespread inflammation. Genetic factors and reactivation of certain dormant viruses are thought to play a role in some cases, which is why the reaction can evolve and sometimes flare even after the drug is stopped.
Risk Factors
DRESS can occur in anyone taking a triggering medication, but some factors may increase risk or guide caution:
- Recent start of a known high-risk medication, especially within the prior several weeks
- Certain genetic backgrounds, which raise the risk with specific drugs
- A previous severe reaction to a related medication
- Possibly a personal or family history of severe drug reactions
Diagnosis
Diagnosis is based on the combination of symptoms, the timing after starting a drug, and laboratory findings. Evaluation includes:
- Medication review: identifying any new drugs started in the previous weeks.
- Blood tests: showing a high eosinophil count, other abnormal white cells, and markers of organ involvement such as liver and kidney function.
- Examination of the rash and lymph nodes.
- Organ assessment: tests of the liver, kidneys, lungs, and sometimes the heart, depending on symptoms.
- Skin biopsy: sometimes performed to support the diagnosis.
Because symptoms can evolve over time, repeated testing may be needed to monitor for delayed organ involvement.
Treatment
Treatment centers on stopping the offending drug and controlling the inflammation, usually in a hospital. Care includes:
- Stopping the responsible medication immediately: the single most important step.
- Corticosteroids: often used to calm the widespread inflammation, especially with organ involvement, and tapered slowly to avoid flares.
- Supportive care: fluids, skin care, and management of fever and organ function.
- Monitoring: close observation for delayed organ problems and for flares that can occur even after the drug is stopped.
- Avoidance: documenting the drug as an allergy so it and related medications are not given again.
Recovery can take weeks, and follow-up is important because some effects, such as thyroid problems, can appear later.
Prevention
DRESS cannot always be prevented, but the risk and harm can be reduced by:
- Telling all healthcare providers about any past severe drug reactions so the drug and related ones are avoided
- Being aware of warning signs when starting a new high-risk medication and seeking care early if a rash and fever develop
- Genetic testing before certain medications when recommended, to identify people at higher risk
- Keeping an up-to-date list of medications and known allergies
- Not restarting a drug suspected of causing a severe reaction
When to See a Doctor
Seek urgent medical care if you develop a spreading rash with fever, facial swelling, swollen glands, or feel severely unwell, especially within the first several weeks of starting a new medication. Tell the medical team exactly which drugs you have recently started.
- Stop the suspected medication and get evaluated as soon as possible.
- Seek emergency care for difficulty breathing, severe rash with blistering or peeling, confusion, or signs that organs are affected, such as yellowing skin or markedly reduced urine.
Frequently Asked Questions
What is DRESS syndrome?
DRESS is a rare, serious delayed reaction to a medication that causes a widespread rash, fever, swollen lymph nodes, a high eosinophil count, and inflammation of internal organs. It typically appears two to eight weeks after starting the responsible drug.
Why does DRESS appear weeks after starting a drug?
DRESS is a delayed immune reaction, so it often develops two to eight weeks after the medication is started. This delay can make the connection to the drug harder to recognize, which is why a careful medication history is so important.
Is DRESS dangerous?
Yes. DRESS can be life-threatening, mainly because of inflammation of organs such as the liver, kidneys, lungs, or heart. It is treated as a medical emergency, and stopping the responsible drug along with prompt treatment is essential.
What is the first step in treating DRESS?
The most important step is stopping the medication that caused it. Treatment usually also includes corticosteroids to control inflammation, supportive care, and close monitoring, often in a hospital, because organ effects and flares can appear or worsen over time.
Can DRESS happen again?
DRESS can recur if the same drug or a closely related medication is taken again, so the responsible drug should be documented as an allergy and avoided. Telling all healthcare providers about the reaction helps prevent a dangerous repeat exposure.
References
- MedlinePlus, U.S. National Library of Medicine. Drug allergies.
- American Academy of Dermatology. Severe drug reactions.
- National Organization for Rare Disorders (NORD). Drug-induced hypersensitivity reactions.
- Centers for Disease Control and Prevention (CDC). Medication safety.