### Date : 2024-12-24 15:18 ### Topic : Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome #endocrinology #hematology ---- ### **Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome** **DRESS syndrome**, also known as **Drug Reaction with Eosinophilia and Systemic Symptoms**, is a severe, potentially life-threatening drug-induced hypersensitivity reaction. It is characterized by a **rash**, **eosinophilia** (elevated levels of eosinophils in the blood), and systemic involvement, including organs such as the liver, kidneys, lungs, and heart. DRESS syndrome typically occurs **2–8 weeks** after starting a drug that triggers the reaction. --- ### **Key Features of DRESS Syndrome** 1. **Rash**: - The most prominent feature is a **morbilliform (measles-like) rash**, often starting on the face and upper body before spreading to other areas. - The rash can progress to involve large areas of the body and may develop into more severe forms, such as **exfoliative dermatitis** or **vesicular eruptions**. 2. **Eosinophilia**: - Blood tests typically show a **marked increase in eosinophils**, which are a type of white blood cell involved in immune responses, particularly in allergic reactions. 3. **Fever**: - **Fever** is a common feature, often accompanying the rash and other systemic symptoms. 4. **Organ Involvement**: - **Liver**: Hepatitis is common in DRESS syndrome, and it can lead to **liver failure** in severe cases. - **Kidneys**: Kidney involvement may present as **acute interstitial nephritis**, leading to renal dysfunction. - **Lungs**: Pulmonary symptoms can include **pneumonitis** or **acute respiratory distress syndrome (ARDS)**. - **Heart**: In some cases, DRESS syndrome can cause **myocarditis** (inflammation of the heart muscle). 5. **Lymphadenopathy**: - **Enlarged lymph nodes** are commonly seen, often reflecting systemic inflammation. --- ### **Common Drugs Associated with DRESS Syndrome** DRESS syndrome is most often triggered by specific medications. Some common culprits include: 1. **Anticonvulsants**: - **Phenytoin** - **Carbamazepine** - **Lamotrigine** 2. **Antibiotics**: - **Sulfonamides** (e.g., **trimethoprim-sulfamethoxazole**) - **Minocycline** - **Allopurinol** (used for gout) 3. **Antiretrovirals**: - **Abacavir** (used for HIV) 4. **Other Drugs**: - **Anti-thyroid drugs** (e.g., **methimazole**) - **Chlorpromazine** (an antipsychotic) - **Diazepam** (a benzodiazepine) - **Nonsteroidal anti-inflammatory drugs (NSAIDs)** --- ### **Pathophysiology of DRESS Syndrome** The exact mechanism behind DRESS syndrome is not fully understood, but it is believed to be an **immune-mediated** hypersensitivity reaction. Several factors contribute: 1. **Drug Metabolism**: - Some drugs are metabolized in the liver into reactive metabolites, which can bind to proteins and trigger an immune response, leading to hypersensitivity. This is thought to be especially true for drugs like **sulfonamides** and **phenytoin**. 2. **Genetic Factors**: - **Genetic predisposition** may play a role in the development of DRESS syndrome. For example, certain **human leukocyte antigen (HLA)** alleles, such as **HLA-B*1502**, have been associated with an increased risk, particularly in individuals of **Asian descent** who are treated with **carbamazepine**. 3. **Immune Activation**: - The immune system becomes activated, leading to **eosinophilia**, **lymphadenopathy**, and **systemic inflammation**. The involvement of multiple organs suggests an overactivation of the **T-cell-mediated immune response**. --- ### **Diagnosis** Diagnosis of DRESS syndrome is based on **clinical criteria** and **laboratory findings**, often requiring the **exclusion of other causes** of symptoms. Common diagnostic approaches include: 1. **Clinical Features**: - **Rash**, **eosinophilia**, **fever**, and **organ involvement** (e.g., liver, kidney). - A thorough **history of drug exposure**, particularly any medications started within the past 2–8 weeks, is crucial. 2. **Laboratory Tests**: - **Complete blood count (CBC)** showing **eosinophilia**. - **Liver function tests (LFTs)** to assess for liver involvement. - **Renal function tests** to check for kidney damage. - **Skin biopsy** or **liver biopsy** in rare cases to confirm the diagnosis and assess organ involvement. 3. **Severity Scores**: - Some centers use **severity scoring systems** (e.g., the **RegiSCAR** scoring system) to determine the likelihood of DRESS syndrome. --- ### **Treatment** Treatment of DRESS syndrome involves several steps: 1. **Discontinuation of the Causative Drug**: - The first and most important step is to **stop the medication** that triggered the reaction. This is crucial to prevent worsening of the symptoms and to avoid additional damage to organs. 2. **Supportive Care**: - **Monitoring** and **treatment of infections**, as patients with DRESS syndrome are at risk of secondary infections due to their compromised immune system. - **Hydration**, **nutritional support**, and **fever management**. 3. **Corticosteroids**: - High-dose **oral corticosteroids** (e.g., **prednisone**) are commonly used to reduce inflammation and immune system activation. Steroid therapy is typically tapered over time. - In severe cases, **IV steroids** (e.g., **methylprednisolone**) may be needed. 4. **Other Immunosuppressants**: - In refractory cases, additional **immunosuppressive drugs** (e.g., **cyclophosphamide**, **mycophenolate mofetil**) may be used. 5. **Management of Organ Involvement**: - Specific treatments are provided for organ damage, such as **liver failure** or **acute renal failure**. This may involve supportive care in an intensive care unit (ICU) for severe cases. --- ### **Prognosis** The prognosis of DRESS syndrome depends on **early recognition** and **appropriate treatment**. If treated promptly, the condition can be reversible, and many individuals recover with minimal long-term effects. However, if left untreated or if organ damage is severe, **liver failure**, **renal failure**, and even **death** can occur. - **Early diagnosis** and **withdrawal of the offending drug** are key to improving outcomes. - Long-term complications, such as **scarring** or **fibrosis**, can occur, particularly in the **liver**. --- ### **Conclusion** **DRESS syndrome** is a **severe drug-induced hypersensitivity reaction** characterized by **eosinophilia**, **rashes**, **fever**, and **organ involvement**. Early recognition and **discontinuation of the causative drug** are essential in managing the condition. **Corticosteroid therapy** is often necessary, and patients may require additional **supportive care** and **immunosuppressants**. Prompt treatment can significantly improve prognosis and reduce the risk of permanent organ damage. ### Reference: - ### Connected Documents: -