DRESS Syndrome: Definition and Diagnosis

Clinical Characteristics

The American College of Dermatology suggests that DRESS syndrome is a severe and potentially life-threatening adverse reaction characterized by skin rash, fever, eosinophilia, and internal organ involvement, typically occurring 2-6 weeks after exposure to the causative drug 1
The European Academy of Allergy and Clinical Immunology recommends that the diagnosis of DRESS syndrome should be based on a combination of clinical and laboratory findings, including fever (>38°C), lymphadenopathy, eosinophilia (>700/μL or >10%), and skin involvement (>30% of body surface area) 1

The National Institute of Allergy and Infectious Diseases states that anticonvulsants and antibiotics are the most common causes of DRESS syndrome, with carbamazepine, phenytoin, and phenobarbital being the most frequently implicated anticonvulsants 1
The British Society for Antimicrobial Chemotherapy notes that vancomycin, trimethoprim-sulfamethoxazole, sulfonamides, and minocycline are common antibiotic causes of DRESS syndrome 3

The RegiSCAR scoring system classifies cases as "no", "possible", "probable", or "definite" based on clinical and laboratory findings, with a score ≥2 indicating possible DRESS syndrome 1
The American Academy of Dermatology recommends that the diagnosis of DRESS syndrome should be based on a combination of clinical and laboratory findings, including fever, lymphadenopathy, eosinophilia, and skin involvement 1

The European Academy of Allergy and Clinical Immunology suggests that a complete blood count with differential, liver function tests, and renal function tests are essential for evaluating patients with suspected DRESS syndrome 1
The National Institute of Allergy and Infectious Diseases recommends that urine analysis and blood cultures should be performed to rule out infectious causes 2

The American College of Dermatology notes that DRESS syndrome must be distinguished from other severe cutaneous reactions, particularly Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) 6
The British Society for Antimicrobial Chemotherapy recommends that the diagnosis of DRESS syndrome should be based on a combination of clinical and laboratory findings, including eosinophilia, lymphadenopathy, and skin involvement 6

The European Academy of Allergy and Clinical Immunology suggests that immediate withdrawal of the suspected drug is the first and most crucial step in managing DRESS syndrome, with urgent dermatological consultation for all suspected cases 2
The American Academy of Dermatology recommends that patients with severe DRESS syndrome should be admitted to a burn unit or intensive care unit, with initiation of methylprednisolone IV and supportive care, including fluid and electrolyte management, infection prevention, and topical treatment 2

The National Institute of Allergy and Infectious Diseases notes that certain HLA associations are strongly linked to specific reactions, such as HLA-B58:01 with allopurinol-induced DRESS syndrome, and HLA-B1502 with carbamazepine in Asian populations 1
The British Society for Antimicrobial Chemotherapy recommends that genetic testing for HLA associations should be considered in patients with a history of DRESS syndrome 4