Introduction
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a severe, potentially life-threatening drug-induced hypersensitivity reaction characterized by extensive rash, fever, lymphadenopathy, hematologic abnormalities, and internal organ involvement. This comprehensive review explores the essential aspects of DRESS syndrome that medical professionals need to understand for accurate diagnosis and appropriate management.
Epidemiology and Risk Factors
The incidence of DRESS syndrome ranges from 1 in 1,000 to 1 in 10,000 drug exposures. Key risk factors include:
- Genetic predisposition, particularly HLA alleles
- Viral reactivation (HHV-6, HHV-7, EBV, CMV)
- Autoimmune conditions
- Previous drug reactions
Pathophysiology
DRESS syndrome involves complex immunological mechanisms:
- Delayed T-cell-mediated hypersensitivity reaction
- Genetic susceptibility involving specific HLA alleles
- Viral reactivation cascade
- Altered drug metabolism leading to reactive metabolites
- Immune system dysregulation
Common Culprit Medications
The most frequently implicated medications include:
- Anticonvulsants (carbamazepine, phenytoin, lamotrigine)
- Allopurinol
- Sulfonamide antibiotics
- Vancomycin
- Minocycline
- Beta-lactam antibiotics
Clinical Manifestations
Cutaneous Features
- Morbilliform rash (>90% of cases)
- Facial edema
- Desquamation
- Mucosal involvement
Systemic Manifestations
- Fever >38.5°C
- Lymphadenopathy
- Visceral involvement
- Hepatitis (60-80%)
- Pneumonitis
- Nephritis
- Myocarditis
- Thyroiditis
Laboratory Findings
- Eosinophilia (>700/μL)
- Atypical lymphocytosis
- Elevated liver enzymes
- Elevated inflammatory markers
Diagnostic Criteria
The RegiSCAR scoring system includes:
- Fever ≥38.5°C
- Enlarged lymph nodes
- Eosinophilia
- Atypical lymphocytes
- Skin involvement
- Organ involvement
- Resolution ≥15 days
- Negative evaluation for other causes
Management Approach
Immediate Actions
- Discontinuation of culprit medication
- Hospitalization for severe cases
- Supportive care
- Monitoring of organ function
Treatment Options
- Systemic corticosteroids
- Initial dose: Prednisolone 0.5-1.0 mg/kg/day
- Gradual tapering over 2-3 months
- Alternative treatments
- IVIG in severe cases
- Cyclosporine for steroid-resistant cases
- Plasmapheresis in selected cases
Monitoring Requirements
- Regular blood counts
- Liver function tests
- Renal function
- Cardiac monitoring if indicated
- Thyroid function tests
Prognosis and Complications
- Mortality rate: 2-10%
- Risk factors for poor outcome
- Older age
- Liver failure
- Respiratory involvement
- Delayed diagnosis
Prevention and Follow-up
Prevention Strategies
- Careful medication history
- Genetic screening in high-risk populations
- Avoiding cross-reactive medications
- Patient education and documentation
Long-term Follow-up
- Regular monitoring for autoimmune sequelae
- Documentation for future medical care
- Genetic counseling if indicated
- Provision of medical alert information
Conclusion
DRESS syndrome remains a challenging diagnosis requiring high clinical suspicion and prompt recognition. Understanding its pathophysiology, clinical features, and management principles is crucial for medical professionals to improve patient outcomes.
Date of last update: December 2024
Disclaimer: This article is intended for medical professionals and students. Clinical judgment should be exercised in the application of this information to patient care.
