Drug Reaction Eosinophilia Systemic Symptoms (DRESS syndrome)

Related Subjects: |Acute Severe Asthma |Eosinophilic granulomatosis (Churg Strauss) |Loffler's syndrome (Pulmonary Eosinophilia) |Pulmonary Eosinophilia and CXR changes |Drug Reaction Eosinophilia Systemic Symptoms

🚨 DRESS Syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) is a life-threatening idiosyncratic drug reaction with mortality of ~10%. It causes a widespread skin eruption, fever, lymphadenopathy, and can involve multiple organs (liver, kidneys, lungs, heart).

📖 About

• Severe, delayed-onset hypersensitivity reaction (latency 2–8 weeks).
• Also called anticonvulsant hypersensitivity syndrome.
• Classified as one of the Severe Cutaneous Adverse Reactions (SCARs) alongside SJS/TEN.

🧪 Aetiology

• Most commonly triggered by aromatic anticonvulsants (carbamazepine, phenytoin, lamotrigine, phenobarbital).
• Other drugs: allopurinol, minocycline, abacavir, nevirapine, vancomycin, sulfonamides, NSAIDs.
• Genetic predisposition (e.g. HLA-B*58:01 and allopurinol in Han Chinese patients).
• Latency: typically 2–6 weeks, longer than most other drug reactions.

💊 High-Risk Drugs

• Anticonvulsants: Carbamazepine, Phenytoin, Lamotrigine, Valproate.
• Anti-infectives: Sulfonamides, Minocycline, Dapsone, Vancomycin, Doxycycline.
• Others: Allopurinol, Abacavir, Nevirapine, Clozapine, Rituximab, NSAIDs.

🩺 Clinical Features

• Onset 2–8 weeks after drug initiation.
• Systemic symptoms: Fever, lymphadenopathy, malaise.
• Skin: Morbilliform/maculopapular eruption, urticaria, vesicles, bullae, target lesions, erythroderma, facial oedema.
• Internal organs: Hepatitis (commonest), nephritis, pneumonitis, myocarditis, colitis.
• May overlap with SJS/TEN or erythema multiforme.

🔬 Investigations

• Bloods: Eosinophilia, atypical lymphocytosis, leukocytosis, abnormal LFTs, renal impairment.
• Rule out other causes (viral hepatitis, EBV/CMV, autoimmune disease).
• RegiSCAR criteria used for standardised diagnosis.

⚕️ Management

• 🚫 Immediate withdrawal of the offending drug (key determinant of prognosis).
• Supportive care: fluids, electrolyte balance, nutritional support.
• Corticosteroids (e.g. Prednisolone) often used if systemic involvement, though evidence is limited.
• Ciclosporin and other immunosuppressants may be used in severe/refractory cases.
• Close ITU/HDU monitoring if multi-organ failure risk.

🛡️ Prevention

• Genetic screening (e.g. HLA-B*58:01 before allopurinol, HLA-B*15:02 before carbamazepine in high-risk populations).
• Educate patients about early warning signs (rash, fever).
• Avoid re-exposure to the offending drug or structurally similar compounds.

📈 Prognosis

• Mortality ~10%, mainly due to fulminant hepatitis or myocarditis.
• Early recognition and drug withdrawal greatly improve outcomes.
• Possible long-term sequelae: chronic kidney disease, autoimmune thyroiditis, type 1 diabetes.

✅ Conclusion

• DRESS is a severe, delayed drug hypersensitivity syndrome with multi-organ involvement.
• Rapid recognition, drug cessation, and supportive care are vital for survival.
• Preventive strategies (genetic testing, education, monitoring) reduce incidence and severity.

📚 References

• Drug reaction with eosinophilia and systemic symptoms (DRESS)
• StatPearls: DRESS Syndrome

3 Clinical Cases - DRESS Syndrome 💊🔥🩸

• Case 1 - Anticonvulsant-related DRESS 🧠: A 27-year-old man started on carbamazepine for epilepsy 5 weeks ago develops fever, widespread morbilliform rash, facial oedema, and lymphadenopathy. Bloods: eosinophilia and raised ALT/AST. Teaching: Classic culprit drugs are aromatic anticonvulsants (carbamazepine, phenytoin, lamotrigine). DRESS typically appears 2–8 weeks after exposure. Management: stop the drug immediately, supportive care, and systemic corticosteroids if organ involvement.
• Case 2 - Antibiotic-induced DRESS 💉: A 45-year-old woman treated with vancomycin for MRSA endocarditis presents with high-grade fever, diffuse erythematous rash, and swelling of the face. Bloods: eosinophilia, atypical lymphocytes, and renal impairment. Teaching: Antibiotics such as vancomycin, minocycline, and sulfonamides can trigger DRESS. Key danger = multi-organ involvement (especially kidney, liver). Withdrawal of the drug + systemic steroids is essential.
• Case 3 - Allopurinol-associated DRESS 🦶: A 68-year-old man recently started on allopurinol for gout prophylaxis develops fever, malaise, extensive exfoliative rash, and marked facial oedema. Bloods: eosinophilia, deranged LFTs, and creatinine rise. Teaching: Allopurinol is a leading cause of DRESS, particularly in older patients with renal impairment. Risk factors include HLA-B*58:01 allele (high prevalence in Asian populations). Stopping the drug promptly is life-saving, with steroids often required.