Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a rare but
severe hypersensitivity reaction that remains poorly characterized in the US. We aimed
to identify and describe DRESS syndrome cases in an integrated healthcare system using
electronic health record (EHR) allergy module free text searches. We identified DRESS
syndrome cases with rash, absolute eosinophil count ≥500/L, organ involvement, and
RegiSCAR (European Registry of Severe Cutaneous Adverse Reactions [SCAR]) to Drugs
and Collection of Biological Samples) score ≥2 by reviewing patients from 1980–2016
whose EHR allergic reaction matched DRESS-related keywords. Liver injury required
alanine aminotransferase ≥100U/L and renal injury required creatinine increase by
≥0.5mg/dL or 50%. Patient and DRESS characteristics were described, resource use was
determined, and cost was estimated. Among 3,162,562 patients with 3,319,387 million
allergy entries, 538 reactions matched keywords, and 69 were DRESS cases (prevalence
2.18 per 100,000). DRESS patients had liver (42%) or renal (42%) injury; 11 (16%)
had both liver and renal injury. Primary drug culprits were antibiotics (74%) (vancomycin
[39%], beta-lactams [23%], fluoroquinolones [4%], tetracyclines [4%], and sulfonamides
[3%]) and anticonvulsants (20%). Of 65(94%) hospitalized DRESS patients, 43 (66%)
were hospitalized for DRESS syndrome management with median length of stay 9 days
[IQR, 6–17 days] and cost approximately $17,101 per patient. Using free text search
of the EHR allergy module identified a large US DRESS syndrome cohort. DRESS prevalence
was 2.18 per 100,000 patients. Both liver and kidney injury were frequent, and vancomycin
was the most common drug culprit. DRESS cases were morbid and resource-intensive.